Back
CVE-2026-74938Mitigation bypass in the JavaScript: GC component
- 9.1CriticalCVSS base score
- 0.44%Exploitation in 30 daysEPSS · top 61% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Mitigation bypass in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Timeline
ID reserved
By mozilla
- 1 day later
· 1 day later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| NVDNVD · Analyzed | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.44% · top 61% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.1.
Affected products
- unaffected 153.1 – ≤ 153.*
- unaffected 154 – ≤ *
- unaffected 153.1 – ≤ 153.*
- unaffected 154 – ≤ *
References
References5
- https://bugzilla.mozilla.org/show_bug.cgi?id=2053688 (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2026-74/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2026-77/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2026-78/ (opens in a new tab)
- https://www.mozilla.org/security/advisories/mfsa2026-80/ (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-60676 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-74938)Record last updated .