CVE-2026-117921
Use-after-free in the CSS Parsing and Computation component
- Risk score
- 65/100
- CVSS
- 8.8 v3.1
- Exploit chance (30 days)
- 0.4%
- Published
- 27 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Amber
- CVSS 8.8 high
- Remotely exploitable without logging in
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2079687
- https://www.mozilla.org/security/advisories/mfsa2026-118/
- https://www.mozilla.org/security/advisories/mfsa2026-119/
- https://www.mozilla.org/security/advisories/mfsa2026-120/
- https://www.mozilla.org/security/advisories/mfsa2026-121/
- https://www.mozilla.org/security/advisories/mfsa2026-122/
Original description
Use-after-free in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
Last activity 27 Oct 2026. Patch Forecast updates every hour.