CVE-2026-2781

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-02-24. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2026-8502 (ENISA EUVD) · GHSA-q6rm-rhj9-jpg5 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Integer overflow in the Libraries component in NSS. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, Thunderbird 140.8, and Firefox ESR 115.35.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
44
EG Risk 44/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
38th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

February 24, 2026

Last Modified

June 17, 2026

Advisory Details (7)

Auto-updated Oct 31, 2026
Patch available.
Web pageMentions a patch (unverified)

[SECURITY] [DLA 4508-1] nss security update

https://lists.debian.org/debian-lts-announce/2026/03/msg00012.html
Web page

Security Vulnerabilities fixed in Firefox ESR 115.35 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-31/
Web page

Security Vulnerabilities fixed in Thunderbird 140.8 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-17/
Web page

Security Vulnerabilities fixed in Thunderbird 148 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-16/
Web page

Security Vulnerabilities fixed in Firefox ESR 140.8 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-15/
Web page

Security Vulnerabilities fixed in Firefox 148 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-13/
Web page

2009552 - (CVE-2026-2781) AES-GCM produces incorrect authentication tags on some platforms for data >= 512 MB due to 32-bit integer overflow in length computation

https://bugzilla.mozilla.org/show_bug.cgi?id=2009552

Patch Availability(27)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibnss3-tools (2:3.28.4-0ubuntu0.14.04.5+esm13) @ trusty2026-11-12ubuntu
ubuntulibnss3-tools (2:3.114-1ubuntu0.1) @ questing2026-11-12ubuntu
redhatthunderbird-0:140.8.0-1.el8_22026-03-12redhat
redhatthunderbird-0:140.8.0-2.el10_02026-03-11redhat
redhatfirefox-0:140.8.0-2.el9_22026-03-10redhat
redhatthunderbird-0:140.8.0-1.el9_22026-03-09redhat
redhatthunderbird-0:140.8.0-2.el8_42026-03-09redhat
redhatthunderbird-0:140.8.0-1.el8_62026-03-09redhat
redhatthunderbird-0:140.8.0-1.el9_02026-03-09redhat
redhatthunderbird-0:140.8.0-1.el9_42026-03-09redhat
redhatfirefox-0:140.8.0-2.el7_92026-03-09redhat
redhatfirefox-0:140.8.0-2.el10_02026-03-09redhat
redhatthunderbird-0:140.8.0-1.el8_82026-03-09redhat
redhatthunderbird-0:140.8.0-1.el9_62026-03-09redhat
redhatthunderbird-0:140.8.0-2.el10_12026-03-02redhat
redhatfirefox-0:140.8.0-2.el8_22026-03-02redhat
redhatfirefox-0:140.8.0-2.el8_82026-03-02redhat
redhatthunderbird-0:140.8.0-1.el8_102026-03-02redhat
redhatfirefox-0:140.8.0-2.el9_42026-03-02redhat
redhatfirefox-0:140.8.0-2.el9_02026-03-02redhat
redhatfirefox-0:140.8.0-2.el9_62026-03-02redhat
redhatfirefox-0:140.8.0-2.el8_62026-03-02redhat
redhatthunderbird-0:140.8.0-1.el9_72026-03-02redhat
redhatfirefox-0:140.8.0-2.el8_42026-03-02redhat
redhatfirefox-0:140.8.0-2.el8_102026-02-25redhat
redhatfirefox-0:140.8.0-2.el9_72026-02-25redhat
redhatfirefox-0:140.8.0-2.el10_12026-02-25redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(12 across 4 ecosystems)
Debian:11(3)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr102.1.0esr-1 ... 91.9.1esr-1~deb9u1 (251 versions)
  • every version up to 140.8.0esr-1~deb11u1: fixed in 140.8.0esr-1~deb11u1
—
nss2:3.61-1, 2:3.61-1+deb11u1, 2:3.61-1+deb11u2, 2:3.61-1+deb11u3, 2:3.61-1+deb11u4
  • every version up to 2:3.61-1+deb11u5: fixed in 2:3.61-1+deb11u5
—
thunderbird1:102.0.1-1 ... 1:91.9.0-1~deb9u1 (302 versions)
  • every version up to 1:140.8.0esr-1~deb11u1: fixed in 1:140.8.0esr-1~deb11u1
—
Debian:12(3)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr102.11.0esr-1 ... 140.8.0esr-1~deb11u1 (158 versions)
  • every version up to 140.8.0esr-1~deb12u1: fixed in 140.8.0esr-1~deb12u1
—
nss2:3.87.1-1, 2:3.87.1-1+deb12u1
  • every version up to 2:3.87.1-1+deb12u2: fixed in 2:3.87.1-1+deb12u2
—
thunderbird1:102.11.0-1 ... 1:140.8.0esr-1~deb11u1 (187 versions)
  • every version up to 1:140.8.0esr-1~deb12u1: fixed in 1:140.8.0esr-1~deb12u1
—
Debian:13(3)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr128.13.0esr-1 ... 140.8.0esr-1~deb12u1 (34 versions)
  • every version up to 140.8.0esr-1~deb13u1: fixed in 140.8.0esr-1~deb13u1
—
nss2:3.110-1
  • every version up to 2:3.110-1+deb13u1: fixed in 2:3.110-1+deb13u1
—
thunderbird1:128.13.0esr-1 ... 1:140.8.0esr-1~deb12u1 (43 versions)
  • every version up to 1:140.8.0esr-1~deb13u1: fixed in 1:140.8.0esr-1~deb13u1
—
Debian:14(3)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr128.13.0esr-1 ... 140.8.0esr-1~deb13u1 (35 versions)
  • every version up to 140.8.0esr-1: fixed in 140.8.0esr-1
—
nss2:3.110-1 ... 2:3.120-1 (8 versions)
  • every version up to 2:3.121-1: fixed in 2:3.121-1
—
thunderbird1:128.13.0esr-1 ... 1:140.8.0esr-1~deb13u1 (44 versions)
  • every version up to 1:140.8.0esr-1: fixed in 1:140.8.0esr-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(5)

Data Freshness Timeline

(refreshed 21× in last 7d / 91× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 426 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 326 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:52 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  2. 2026-11-13 06:44 UTCEchelonGraph re-scored
  3. 2026-11-13 06:44 UTCVendor advisory
  4. 2026-11-13 06:44 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  6. 2026-11-12 07:15 UTCEchelonGraph re-scored
  7. 2026-11-12 07:15 UTCVendor advisory
  8. 2026-11-12 07:15 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-11-11 16:39 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  10. 2026-11-11 07:43 UTCEchelonGraph re-scored
  11. 2026-11-11 07:43 UTCVendor advisory
  12. 2026-11-11 07:43 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-11-10 16:43 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  14. 2026-11-10 08:13 UTCEchelonGraph re-scored
  15. 2026-11-10 08:13 UTCVendor advisory
  16. 2026-11-10 08:13 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  18. 2026-11-09 08:44 UTCEchelonGraph re-scored
  19. 2026-11-09 08:44 UTCVendor advisory
  20. 2026-11-09 08:44 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  22. 2026-11-08 09:15 UTCEchelonGraph re-scored
  23. 2026-11-08 09:15 UTCVendor advisory
  24. 2026-11-08 09:15 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-11-07 16:38 UTCEPSS rescoreEPSS 0.4% · 37th percentile
Show 75 more
  1. 2026-11-07 09:46 UTCEchelonGraph re-scored
  2. 2026-11-07 09:46 UTCVendor advisory
  3. 2026-11-07 09:46 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-06 16:37 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  5. 2026-11-06 10:16 UTCEchelonGraph re-scored
  6. 2026-11-06 10:16 UTCVendor advisory
  7. 2026-11-06 10:16 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-11-06 04:55 UTCOSV refresh
  9. 2026-11-05 16:37 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  10. 2026-11-05 10:45 UTCEchelonGraph re-scored
  11. 2026-11-05 10:45 UTCVendor advisory
  12. 2026-11-05 10:45 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  14. 2026-11-04 11:16 UTCEchelonGraph re-scored
  15. 2026-11-04 11:16 UTCVendor advisory
  16. 2026-11-04 11:16 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-11-03 16:47 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  18. 2026-11-03 11:47 UTCEchelonGraph re-scored
  19. 2026-11-03 11:47 UTCVendor advisory
  20. 2026-11-03 11:47 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  22. 2026-11-02 12:18 UTCEchelonGraph re-scored
  23. 2026-11-02 12:18 UTCVendor advisory
  24. 2026-11-02 12:17 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  26. 2026-11-01 12:49 UTCEchelonGraph re-scored
  27. 2026-11-01 12:49 UTCVendor advisory
  28. 2026-11-01 12:49 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  30. 2026-10-31 13:20 UTCEchelonGraph re-scored
  31. 2026-10-31 13:20 UTCVendor advisory
  32. 2026-10-31 13:20 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  34. 2026-10-30 13:50 UTCEchelonGraph re-scored
  35. 2026-10-30 13:50 UTCVendor advisory
  36. 2026-10-30 13:50 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  38. 2026-10-29 14:22 UTCEchelonGraph re-scored
  39. 2026-10-29 14:22 UTCVendor advisory
  40. 2026-10-29 14:22 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  42. 2026-10-28 14:53 UTCEchelonGraph re-scored
  43. 2026-10-28 14:53 UTCVendor advisory
  44. 2026-10-28 14:53 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  45. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  46. 2026-10-27 14:53 UTCEchelonGraph re-scored
  47. 2026-10-27 14:53 UTCVendor advisory
  48. 2026-10-27 14:53 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  49. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  50. 2026-10-26 15:22 UTCEchelonGraph re-scored
  51. 2026-10-26 15:22 UTCVendor advisory
  52. 2026-10-26 15:22 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  54. 2026-10-25 15:01 UTCVendor advisory
  55. 2026-10-25 15:01 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  56. 2026-10-25 14:38 UTCEchelonGraph re-scored
  57. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  58. 2026-10-24 15:31 UTCEchelonGraph re-scored
  59. 2026-10-24 15:31 UTCVendor advisory
  60. 2026-10-24 15:31 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  62. 2026-10-23 16:01 UTCEchelonGraph re-scored
  63. 2026-10-23 16:01 UTCVendor advisory
  64. 2026-10-23 16:01 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  66. 2026-10-22 16:30 UTCEchelonGraph re-scored
  67. 2026-10-22 16:30 UTCVendor advisory
  68. 2026-10-22 16:30 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  70. 2026-10-21 16:22 UTCVendor advisory
  71. 2026-10-21 16:22 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-10-20 16:52 UTCEchelonGraph re-scored
  73. 2026-10-20 16:52 UTCVendor advisory
  74. 2026-10-20 16:52 UTCGHSA enrichmentGHSA-q6rm-rhj9-jpg5 · GitHub severity CRITICAL · GitHub CVSS 9.8
  75. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.6% · 46th percentile

Frequently asked(5)

What is CVE-2026-2781?
CVE-2026-2781 is a critical-severity vulnerability; its CVE record was published on February 24, 2026. Integer overflow in the Libraries component in NSS. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, Thunderbird 140.8, and Firefox ESR 115.35.
When was the CVE record for CVE-2026-2781 published?
The CVE record for CVE-2026-2781 was published on February 24, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of June 17, 2026; the record at its source may have been updated since.
Is CVE-2026-2781 actively exploited?
CVE-2026-2781 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (38th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-2781?
CVE-2026-2781 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-2781?
A fix for CVE-2026-2781 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-2781 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-2781

Explore →

Is Your Infrastructure Affected by CVE-2026-2781?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.