CVE-2026-74944

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-18. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
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: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

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%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
34%
KEV
Not listed

Published

August 18, 2026

Last Modified

August 21, 2026

Advisory Details (7)

Auto-updated Sep 18, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 153.1 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-80/
generic

Security Vulnerabilities fixed in Thunderbird 140.14 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-79/
generic

Security Vulnerabilities fixed in Thunderbird 154 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-78/
generic

Security Vulnerabilities fixed in Firefox ESR 153.1 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-77/
generic

Security Vulnerabilities fixed in Firefox ESR 140.14 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-76/
generic

Security Vulnerabilities fixed in Firefox 154 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-74/

Patch Availability(15)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatthunderbird-0:140.14.0-1.el9_22026-09-09redhat
redhatfirefox-0:140.14.0-1.el9_22026-09-09redhat
redhatfirefox-0:140.14.0-1.el8_82026-09-08redhat
redhatthunderbird-0:140.14.0-1.el9_82026-09-08redhat
redhatfirefox-0:140.14.0-1.el9_62026-09-08redhat
redhatfirefox-0:140.14.0-1.el10_02026-09-08redhat
redhatfirefox-0:140.14.0-1.el7_92026-09-08redhat
redhatthunderbird-0:140.14.0-1.el9_42026-09-08redhat
redhatfirefox-0:140.14.0-1.el8_42026-09-08redhat
redhatfirefox-0:140.14.0-1.el8_62026-09-08redhat
redhatfirefox-0:140.14.0-1.el9_42026-09-08redhat
redhatthunderbird-0:140.14.0-1.el9_62026-09-08redhat
redhatfirefox-0:140.14.0-1.el9_82026-08-24redhat
redhatfirefox-0:140.14.0-1.el8_102026-08-24redhat
redhatfirefox-0:140.14.0-1.el10_22026-08-24redhat

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

(6 across 3 ecosystems)
Debian:12(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.11.0esr-1 ... 140.9.1esr-1~deb13u1 (195 versions)140.14.0esr-1~deb12u1
thunderbird1:102.11.0-1 ... 1:140.9.1esr-1~deb13u1 (224 versions)1:140.14.0esr-1~deb12u1
Debian:13(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (71 versions)140.14.0esr-1~deb13u1
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (80 versions)1:140.14.0esr-1~deb13u1
Debian:14(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (72 versions)140.14.0esr-2
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (81 versions)1:140.14.0esr-1

Weakness Classification(1)

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

Additional Vendor Advisories

(2)

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 88× in last 7d / 347× 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 355 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-74944?
CVE-2026-74944 is a critical vulnerability published on August 18, 2026. Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
When was CVE-2026-74944 disclosed?
CVE-2026-74944 was first published in the National Vulnerability Database on August 18, 2026, with the most recent update on August 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-74944 actively exploited?
CVE-2026-74944 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 65.7% of all scored CVEs.
What is the CVSS score of CVE-2026-74944?
CVE-2026-74944 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-74944?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-74944, 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-2026-74944

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