EUVD-2026-14857CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
4Description
Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9.
Analysis
Multiple memory safety bugs affecting Firefox, Firefox ESR, and Thunderbird browsers present a critical remote code execution risk through memory corruption vulnerabilities. The affected versions include Firefox below 149, Firefox ESR below 115.34 and 140.9, Thunderbird ESR 140.8, Firefox 148, and Thunderbird 148. …
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Remediation
Within 24 hours: Identify all affected systems and apply vendor patches immediately. If patching is delayed, consider network segmentation to limit exposure.
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Priority Score
Vendor Status
Debian
| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| sid | vulnerable | 148.0.2-1 | - |
| (unstable) | fixed | (unfixed) | - |
| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| bullseye | vulnerable | 115.14.0esr-1~deb11u1 | - |
| bullseye (security) | vulnerable | 140.8.0esr-1~deb11u1 | - |
| bookworm | vulnerable | 128.14.0esr-1~deb12u1 | - |
| bookworm (security) | vulnerable | 140.8.0esr-1~deb12u1 | - |
| trixie (security), trixie | vulnerable | 140.8.0esr-1~deb13u1 | - |
| forky, sid | vulnerable | 140.8.0esr-1 | - |
| (unstable) | fixed | (unfixed) | - |
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External POC / Exploit Code
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