CVE-2026-4705

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 2026-03-24. 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-2026-14825 (ENISA EUVD) · GHSA-mrxg-j2xh-wg8q (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Undefined behavior in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

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.
Exploitation0.7% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.7%
EPSS %ILE
52nd
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
0.7% 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; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days 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; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (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)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

March 24, 2026

Last Modified

June 17, 2026

Advisory Details (5)

Auto-updated Oct 31, 2026
Patch available.
Web page

Security Vulnerabilities fixed in Thunderbird 140.9 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-24/
Web page

Security Vulnerabilities fixed in Thunderbird 149 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-23/
Web page

Security Vulnerabilities fixed in Firefox ESR 140.9 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-22/
Web page

Security Vulnerabilities fixed in Firefox 149 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-20/
Web page

2014873 - (CVE-2026-4705) Assertion failure: it != mSsrcToRtxSsrc.end(), at /dom/media/webrtc/jsep/JsepTrack.h:176

https://bugzilla.mozilla.org/show_bug.cgi?id=2014873

Patch Availability(25)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatthunderbird-0:140.9.0-1.el8_42026-04-20redhat
redhatfirefox-0:140.9.0-1.el7_92026-04-16redhat
redhatthunderbird-0:140.9.0-1.el8_82026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_42026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_62026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_22026-04-15redhat
redhatthunderbird-0:140.9.0-1.el10_02026-04-15redhat
redhatthunderbird-0:140.9.0-1.el8_62026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_22026-04-15redhat
redhatthunderbird-0:140.9.0-1.el9_02026-04-15redhat
redhatfirefox-0:140.9.0-1.el9_02026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_62026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_62026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_42026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_42026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_22026-04-13redhat
redhatfirefox-0:140.9.0-1.el8_82026-04-13redhat
redhatfirefox-0:140.9.0-1.el9_22026-04-13redhat
redhatfirefox-0:140.9.0-1.el10_02026-04-13redhat
redhatthunderbird-0:140.9.0-1.el8_102026-04-07redhat
redhatthunderbird-0:140.9.0-1.el10_12026-04-01redhat
redhatthunderbird-0:140.9.0-1.el9_72026-03-30redhat
redhatfirefox-0:140.9.0-1.el10_12026-03-26redhat
redhatfirefox-0:140.9.0-1.el8_102026-03-26redhat
redhatfirefox-0:140.9.0-1.el9_72026-03-26redhat

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

(8 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr102.1.0esr-1 ... 91.9.1esr-1~deb9u1 (255 versions)
  • every version up to 140.9.0esr-1~deb11u1: fixed in 140.9.0esr-1~deb11u1
—
thunderbird1:102.0.1-1 ... 1:91.9.0-1~deb9u1 (306 versions)
  • every version up to 1:140.9.0esr-1~deb11u1: fixed in 1:140.9.0esr-1~deb11u1
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr102.11.0esr-1 ... 140.8.0esr-1~deb13u1 (161 versions)
  • every version up to 140.9.0esr-1~deb12u1: fixed in 140.9.0esr-1~deb12u1
—
thunderbird1:102.11.0-1 ... 1:140.9.0esr-1~deb11u1 (191 versions)
  • every version up to 1:140.9.0esr-1~deb12u1: fixed in 1:140.9.0esr-1~deb12u1
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr128.13.0esr-1 ... 140.8.0esr-1~deb13u1 (36 versions)
  • every version up to 140.9.0esr-1~deb13u1: fixed in 140.9.0esr-1~deb13u1
—
thunderbird1:128.13.0esr-1 ... 1:140.9.0esr-1~deb11u1 (46 versions)
  • every version up to 1:140.9.0esr-1~deb13u1: fixed in 1:140.9.0esr-1~deb13u1
—
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
firefox-esr128.13.0esr-1 ... 140.9.0esr-1~deb13u1 (39 versions)
  • every version up to 140.9.0esr-1: fixed in 140.9.0esr-1
—
thunderbird1:128.13.0esr-1 ... 1:140.9.0esr-1~deb13u1 (48 versions)
  • every version up to 1:140.9.0esr-1: fixed in 1:140.9.0esr-1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(5)

Data Freshness Timeline

(refreshed 23× in last 7d / 94× 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 414 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 314 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 05:41 UTCEchelonGraph re-scored
  2. 2026-11-13 05:41 UTCVendor advisory
  3. 2026-11-13 05:41 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  5. 2026-11-12 07:02 UTCEchelonGraph re-scored
  6. 2026-11-12 07:02 UTCVendor advisory
  7. 2026-11-12 07:02 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  8. 2026-11-11 16:39 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  9. 2026-11-11 08:23 UTCEchelonGraph re-scored
  10. 2026-11-11 08:23 UTCVendor advisory
  11. 2026-11-11 08:22 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  13. 2026-11-10 09:43 UTCEchelonGraph re-scored
  14. 2026-11-10 09:43 UTCVendor advisory
  15. 2026-11-10 09:43 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  17. 2026-11-09 11:03 UTCEchelonGraph re-scored
  18. 2026-11-09 11:03 UTCVendor advisory
  19. 2026-11-09 11:03 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  20. 2026-11-08 16:39 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  21. 2026-11-08 12:24 UTCEchelonGraph re-scored
  22. 2026-11-08 12:24 UTCVendor advisory
  23. 2026-11-08 12:24 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  25. 2026-11-07 13:44 UTCEchelonGraph re-scored
Show 75 more
  1. 2026-11-07 13:44 UTCVendor advisory
  2. 2026-11-07 13:44 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-11-06 16:38 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  4. 2026-11-06 15:05 UTCEchelonGraph re-scored
  5. 2026-11-06 15:05 UTCVendor advisory
  6. 2026-11-06 15:05 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  8. 2026-11-05 16:26 UTCVendor advisory
  9. 2026-11-05 16:26 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  10. 2026-11-04 17:42 UTCEchelonGraph re-scored
  11. 2026-11-04 17:42 UTCVendor advisory
  12. 2026-11-04 17:42 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  14. 2026-11-03 19:02 UTCEchelonGraph re-scored
  15. 2026-11-03 19:02 UTCVendor advisory
  16. 2026-11-03 19:02 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  17. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  18. 2026-11-02 20:23 UTCEchelonGraph re-scored
  19. 2026-11-02 20:23 UTCVendor advisory
  20. 2026-11-02 20:23 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  22. 2026-11-01 21:44 UTCEchelonGraph re-scored
  23. 2026-11-01 21:44 UTCVendor advisory
  24. 2026-11-01 21:44 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  26. 2026-10-31 23:05 UTCEchelonGraph re-scored
  27. 2026-10-31 23:05 UTCVendor advisory
  28. 2026-10-31 23:05 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  29. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  30. 2026-10-31 00:25 UTCEchelonGraph re-scored
  31. 2026-10-31 00:25 UTCVendor advisory
  32. 2026-10-31 00:25 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  34. 2026-10-30 01:46 UTCEchelonGraph re-scored
  35. 2026-10-30 01:46 UTCVendor advisory
  36. 2026-10-30 01:46 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  38. 2026-10-29 03:07 UTCEchelonGraph re-scored
  39. 2026-10-29 03:07 UTCVendor advisory
  40. 2026-10-29 03:07 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  42. 2026-10-28 04:28 UTCEchelonGraph re-scored
  43. 2026-10-28 04:28 UTCVendor advisory
  44. 2026-10-28 04:28 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  45. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  46. 2026-10-27 05:47 UTCEchelonGraph re-scored
  47. 2026-10-27 05:47 UTCVendor advisory
  48. 2026-10-27 05:47 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  49. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  50. 2026-10-26 03:06 UTCEchelonGraph re-scored
  51. 2026-10-26 03:06 UTCVendor advisory
  52. 2026-10-26 03:06 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  54. 2026-10-25 14:24 UTCEchelonGraph re-scored
  55. 2026-10-25 04:26 UTCEchelonGraph re-scored
  56. 2026-10-25 04:26 UTCVendor advisory
  57. 2026-10-25 04:26 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  58. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  59. 2026-10-24 05:47 UTCEchelonGraph re-scored
  60. 2026-10-24 05:47 UTCVendor advisory
  61. 2026-10-24 05:47 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  62. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  63. 2026-10-23 07:06 UTCEchelonGraph re-scored
  64. 2026-10-23 07:06 UTCVendor advisory
  65. 2026-10-23 07:05 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  66. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  67. 2026-10-22 08:22 UTCEchelonGraph re-scored
  68. 2026-10-22 08:22 UTCVendor advisory
  69. 2026-10-22 08:22 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  70. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  71. 2026-10-21 09:44 UTCEchelonGraph re-scored
  72. 2026-10-21 09:44 UTCVendor advisory
  73. 2026-10-21 09:44 UTCGHSA enrichmentGHSA-mrxg-j2xh-wg8q · GitHub severity CRITICAL · GitHub CVSS 9.8
  74. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  75. 2026-10-20 11:05 UTCEchelonGraph re-scored

Frequently asked(5)

What is CVE-2026-4705?
CVE-2026-4705 is a critical-severity vulnerability; its CVE record was published on March 24, 2026. Undefined behavior in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
When was the CVE record for CVE-2026-4705 published?
The CVE record for CVE-2026-4705 was published on March 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-2026-4705 actively exploited?
CVE-2026-4705 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (52nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-4705?
CVE-2026-4705 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-4705?
A fix for CVE-2026-4705 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-4705 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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