CVE-2026-16371

CRITICALPre-NVD 8.89.8▲
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-21. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 8.8; sources differ by 1.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 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: 0%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, Thunderbird 140.13, Firefox ESR 140.15, and Thunderbird 140.15.

CVSS v3
8.8
EG Score
9.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: 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%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

July 21, 2026

Last Modified

September 1, 2026

Advisory Details (5)

Auto-updated Jul 24, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic🔴 Active Exploitation

Security Vulnerabilities fixed in Thunderbird 140.13 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-72/
generic

Security Vulnerabilities fixed in Thunderbird 153 — Mozilla

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

Security Vulnerabilities fixed in Firefox ESR 140.13 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-70/
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=2008369

Vendor Advisories for CVE-2026-16371(20)

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

Patch Availability(21)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatfirefox-0:140.13.0-1.el10_02026-08-12redhat
redhatfirefox-0:140.13.0-1.el8_42026-08-12redhat
redhatfirefox-0:140.13.0-1.el8_82026-08-12redhat
redhatfirefox-0:140.13.0-1.el9_62026-08-12redhat
redhatfirefox-0:140.13.0-1.el7_92026-08-12redhat
redhatfirefox-0:140.13.0-1.el9_22026-08-12redhat
redhatfirefox-0:140.13.0-1.el9_42026-08-12redhat
redhatfirefox-0:140.13.0-1.el8_62026-08-12redhat
redhatthunderbird-0:140.13.0-1.el9_62026-08-11redhat
redhatthunderbird-0:140.13.0-1.el8_42026-08-11redhat
redhatthunderbird-0:140.13.0-1.el8_62026-08-11redhat
redhatthunderbird-0:140.13.0-1.el8_82026-08-11redhat
redhatthunderbird-0:140.13.0-1.el9_22026-08-11redhat
redhatthunderbird-0:140.13.0-1.el9_42026-08-11redhat
redhatthunderbird-0:140.13.0-1.el10_02026-08-11redhat
redhatthunderbird-0:140.13.0-1.el8_102026-08-04redhat
redhatthunderbird-0:140.13.0-1.el9_82026-08-04redhat
redhatthunderbird-0:140.13.0-1.el10_22026-08-03redhat
redhatfirefox-0:140.13.0-1.el9_82026-08-03redhat
redhatfirefox-0:140.13.0-1.el10_22026-07-28redhat
redhatfirefox-0:140.13.0-1.el8_102026-07-28redhat

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 rangeFixed inDependents
firefox-esr102.1.0esr-1 ... 91.9.1esr-1~deb9u1 (283 versions)140.13.0esr-1~deb11u1—
thunderbird1:102.0.1-1 ... 1:91.9.0-1~deb9u1 (334 versions)1:140.13.0esr-1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.11.0esr-1 ... 140.9.1esr-1~deb13u1 (198 versions)140.15.0esr-1~deb12u1—
thunderbird1:102.11.0-1 ... 1:140.9.1esr-1~deb13u1 (227 versions)1:140.15.0esr-1~deb12u1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (74 versions)140.15.0esr-1~deb13u1—
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (83 versions)1:140.15.0esr-1~deb13u1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (75 versions)140.15.0esr-1—
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (73 versions)1:140.13.0esr-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 42× in last 7d / 247× 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 561 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-16371?
CVE-2026-16371 is a critical vulnerability published on July 21, 2026. Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, Thunderbird 140.13, Firefox ESR 140.15, and Thunderbird 140.15.
When was CVE-2026-16371 disclosed?
CVE-2026-16371 was first published in the National Vulnerability Database on July 21, 2026, with the most recent update on September 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16371 actively exploited?
CVE-2026-16371 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 77.8% of all scored CVEs.
What is the CVSS score of CVE-2026-16371?
CVE-2026-16371 has a CVSS v3.1 base score of 8.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.8.
How do I remediate CVE-2026-16371?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-16371, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-16371

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