CVE-2026-16389

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-21. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Incorrect boundary conditions, integer overflow in the Libraries component in NSS. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
59(Track)
EG Risk 59/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
46%
KEV
Not listed

Published

July 21, 2026

Last Modified

August 10, 2026

Advisory Details (4)

Auto-updated Sep 14, 2026
Patch available.
generic Patch Available

[SECURITY] [DLA 4729-1] nss security update

https://lists.debian.org/debian-lts-announce/2026/08/msg00019.html
generic

Security Vulnerabilities fixed in Thunderbird 153 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-71/
generic

Security Vulnerabilities fixed in Firefox 153 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-68/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2043887

Vendor Advisories for CVE-2026-16389(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
nss2:3.100-1 ... 2:3.99-1 (65 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
nss2:3.87.1-1, 2:3.87.1-1+deb12u1, 2:3.87.1-1+deb12u2, 2:3.87.1-1+deb12u32:3.87.1-1+deb12u4—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
nss2:3.110-1, 2:3.110-1+deb13u1, 2:3.110-1+deb13u2, 2:3.110-1+deb13u32:3.110-1+deb13u4—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
nss2:3.110-1 ... 2:3.124-1 (12 versions)2:3.126-1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 113× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 343 total refreshes for this CVE.

  1. 2026-09-20 06:00 UTCEG score recompute
  2. 2026-09-20 06:00 UTCGHSA enrichment
  3. 2026-09-19 00:24 UTCEG score recompute
  4. 2026-09-19 00:24 UTCGHSA enrichment
  5. 2026-09-18 19:27 UTCEPSS rescore
  6. 2026-09-18 07:52 UTCGHSA enrichment
  7. 2026-09-18 03:51 UTCEG score recompute
  8. 2026-09-18 03:51 UTCGHSA enrichment
  9. 2026-09-17 09:53 UTCGHSA enrichment
  10. 2026-09-17 05:07 UTCEG score recompute
  11. 2026-09-17 05:07 UTCGHSA enrichment
  12. 2026-09-16 14:07 UTCEPSS rescore
  13. 2026-09-16 12:41 UTCEG score recompute
  14. 2026-09-16 12:41 UTCGHSA enrichment
  15. 2026-09-16 05:14 UTCEPSS rescore
  16. 2026-09-14 10:51 UTCGHSA enrichment
  17. 2026-09-14 06:51 UTCGHSA enrichment
  18. 2026-09-14 02:50 UTCGHSA enrichment
  19. 2026-09-13 22:41 UTCEG score recompute
  20. 2026-09-13 22:41 UTCGHSA enrichment
  21. 2026-09-13 16:46 UTCEPSS rescore
  22. 2026-09-13 15:58 UTCGHSA enrichment
  23. 2026-09-13 11:26 UTCGHSA enrichment
  24. 2026-09-13 07:03 UTCGHSA enrichment
  25. 2026-09-13 03:03 UTCGHSA enrichment
Show 75 more
  1. 2026-09-12 19:14 UTCEG score recompute
  2. 2026-09-12 19:14 UTCGHSA enrichment
  3. 2026-09-12 15:00 UTCEPSS rescore
  4. 2026-09-12 13:50 UTCGHSA enrichment
  5. 2026-09-12 09:49 UTCGHSA enrichment
  6. 2026-09-12 05:48 UTCGHSA enrichment
  7. 2026-09-12 01:03 UTCGHSA enrichment
  8. 2026-09-11 18:17 UTCEG score recompute
  9. 2026-09-11 18:17 UTCGHSA enrichment
  10. 2026-09-11 14:52 UTCEPSS rescore
  11. 2026-09-11 09:36 UTCEPSS rescore
  12. 2026-09-11 09:09 UTCEG score recompute
  13. 2026-09-11 09:09 UTCGHSA enrichment
  14. 2026-09-10 09:34 UTCEPSS rescore
  15. 2026-09-09 11:36 UTCEG score recompute
  16. 2026-09-09 11:36 UTCGHSA enrichment
  17. 2026-09-08 22:00 UTCEPSS rescore
  18. 2026-09-08 02:41 UTCGHSA enrichment
  19. 2026-09-07 22:41 UTCEG score recompute
  20. 2026-09-07 22:41 UTCGHSA enrichment
  21. 2026-09-07 16:01 UTCEPSS rescore
  22. 2026-09-06 15:47 UTCEG score recompute
  23. 2026-09-06 15:47 UTCGHSA enrichment
  24. 2026-09-06 13:47 UTCEPSS rescore
  25. 2026-09-06 11:04 UTCGHSA enrichment
  26. 2026-09-06 04:04 UTCGHSA enrichment
  27. 2026-09-05 23:51 UTCGHSA enrichment
  28. 2026-09-05 19:51 UTCEG score recompute
  29. 2026-09-05 19:51 UTCGHSA enrichment
  30. 2026-09-05 09:09 UTCEG score recompute
  31. 2026-09-05 09:09 UTCGHSA enrichment
  32. 2026-09-04 05:06 UTCEPSS rescore
  33. 2026-09-02 14:11 UTCEPSS rescore
  34. 2026-09-02 00:59 UTCEG score recompute
  35. 2026-09-02 00:59 UTCGHSA enrichment
  36. 2026-09-01 13:53 UTCEPSS rescore
  37. 2026-09-01 04:39 UTCEPSS rescore
  38. 2026-08-31 03:27 UTCGHSA enrichment
  39. 2026-08-30 23:26 UTCGHSA enrichment
  40. 2026-08-30 19:23 UTCEG score recompute
  41. 2026-08-30 19:23 UTCGHSA enrichment
  42. 2026-08-30 19:17 UTCEPSS rescore
  43. 2026-08-30 15:23 UTCGHSA enrichment
  44. 2026-08-30 10:55 UTCGHSA enrichment
  45. 2026-08-30 06:23 UTCGHSA enrichment
  46. 2026-08-30 02:21 UTCEG score recompute
  47. 2026-08-30 02:21 UTCGHSA enrichment
  48. 2026-08-30 01:22 UTCEPSS rescore
  49. 2026-08-28 21:41 UTCEPSS rescore
  50. 2026-08-28 01:39 UTCGHSA enrichment
  51. 2026-08-27 21:18 UTCEG score recompute
  52. 2026-08-27 21:18 UTCGHSA enrichment
  53. 2026-08-27 14:25 UTCEPSS rescore
  54. 2026-08-27 11:24 UTCGHSA enrichment
  55. 2026-08-27 01:33 UTCGHSA enrichment
  56. 2026-08-26 21:33 UTCEG score recompute
  57. 2026-08-26 21:33 UTCGHSA enrichment
  58. 2026-08-26 14:46 UTCEPSS rescore
  59. 2026-08-26 11:54 UTCGHSA enrichment
  60. 2026-08-26 07:53 UTCGHSA enrichment
  61. 2026-08-26 03:42 UTCGHSA enrichment
  62. 2026-08-25 23:42 UTCGHSA enrichment
  63. 2026-08-25 18:55 UTCGHSA enrichment
  64. 2026-08-25 14:54 UTCEG score recompute
  65. 2026-08-25 14:54 UTCGHSA enrichment
  66. 2026-08-25 13:48 UTCEPSS rescore
  67. 2026-08-25 10:53 UTCGHSA enrichment
  68. 2026-08-25 06:53 UTCGHSA enrichment
  69. 2026-08-25 02:52 UTCGHSA enrichment
  70. 2026-08-24 22:51 UTCGHSA enrichment
  71. 2026-08-24 18:51 UTCEG score recompute
  72. 2026-08-24 18:51 UTCGHSA enrichment
  73. 2026-08-24 13:00 UTCEG score recompute
  74. 2026-08-24 13:00 UTCGHSA enrichment
  75. 2026-08-24 08:59 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-16389?
CVE-2026-16389 is a critical vulnerability published on July 21, 2026. Incorrect boundary conditions, integer overflow in the Libraries component in NSS. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
When was CVE-2026-16389 disclosed?
CVE-2026-16389 was first published in the National Vulnerability Database on July 21, 2026, with the most recent update on August 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16389 actively exploited?
CVE-2026-16389 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 54.3% of all scored CVEs.
What is the CVSS score of CVE-2026-16389?
CVE-2026-16389 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-16389?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-16389, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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