CVE-2026-8957

HIGHNVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.8 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 68% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
8.8EG
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 Enterprise Policies component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity88% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

May 19, 2026

Last Modified

May 20, 2026

Advisory Details (5)

Auto-updated May 20, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 140.11 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-51/
generic

Security Vulnerabilities fixed in Thunderbird 151 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-50/
generic

Security Vulnerabilities fixed in Firefox ESR 140.11 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-48/
generic

Security Vulnerabilities fixed in Firefox 151 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-46/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2033850

Vendor Advisories for CVE-2026-8957(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-0:140.11.0-1.el10_02026-06-22redhat
redhatthunderbird-0:140.11.0-1.el9_62026-06-17redhat
redhatfirefox-0:140.11.0-1.el9_22026-06-17redhat
redhatthunderbird-0:140.11.0-1.el10_02026-06-17redhat
redhatfirefox-0:140.11.0-1.el8_42026-06-17redhat
redhatfirefox-0:140.11.0-1.el8_62026-06-17redhat
redhatfirefox-0:140.11.0-1.el7_92026-06-17redhat
redhatfirefox-0:140.11.0-1.el8_82026-06-17redhat
redhatthunderbird-0:140.11.0-1.el8_62026-06-17redhat
redhatfirefox-0:140.11.0-1.el9_42026-06-17redhat
redhatfirefox-0:140.11.0-1.el9_62026-06-17redhat
redhatthunderbird-0:140.11.0-1.el9_42026-06-16redhat
redhatthunderbird-0:140.11.0-1.el8_42026-06-16redhat
redhatthunderbird-0:140.11.0-1.el9_22026-06-16redhat
redhatthunderbird-0:140.11.0-1.el8_82026-06-16redhat
redhatthunderbird-0:140.11.0-1.el8_102026-06-03redhat
redhatthunderbird-0:140.11.0-1.el10_22026-06-01redhat
redhatfirefox-0:140.11.0-1.el10_22026-05-27redhat
redhatfirefox-0:140.11.0-1.el8_102026-05-27redhat
redhatfirefox-0:140.11.0-1.el9_82026-05-27redhat
redhatthunderbird-0:140.11.0-1.el9_82026-05-27redhat

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 (275 versions)140.11.0esr-1~deb11u1—
thunderbird1:102.0.1-1 ... 1:91.9.0-1~deb9u1 (326 versions)1:140.11.0esr-1~deb11u1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.11.0esr-1 ... 140.9.1esr-1~deb13u1 (182 versions)140.11.0esr-1~deb12u1—
thunderbird1:102.11.0-1 ... 1:140.9.1esr-1~deb13u1 (211 versions)1:140.11.0esr-1~deb12u1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (58 versions)140.11.0esr-1~deb13u1—
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (67 versions)1:140.11.0esr-1~deb13u1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (59 versions)140.11.0esr-1—
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (68 versions)1:140.11.0esr-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 15× in last 7d / 109× 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 222 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-8957?
CVE-2026-8957 is a high vulnerability published on May 19, 2026. Privilege escalation in the Enterprise Policies component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
When was CVE-2026-8957 disclosed?
CVE-2026-8957 was first published in the National Vulnerability Database on May 19, 2026, with the most recent update on May 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8957 actively exploited?
CVE-2026-8957 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 68.6% of all scored CVEs.
What is the CVSS score of CVE-2026-8957?
CVE-2026-8957 has a CVSS v3 base score of 8.8 (NVD).
How do I remediate CVE-2026-8957?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8957, 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-2026-8957

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