CVE-2026-12291: Vulnerability in Mozilla Firefox
CVE-2026-12291 is a use-after-free vulnerability in the Networking: HTTP component of Mozilla Firefox. This security flaw was addressed and fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. The vulnerability is considered high impact due to the potential memory safety risks it poses. There are no known exploits in the wild at this time. Users of affected Firefox versions are advised to update to the fixed versions to mitigate the risk.
AI Analysis
Technical Summary
CVE-2026-12291 is a use-after-free vulnerability affecting the Networking: HTTP component in Mozilla Firefox. This type of vulnerability can lead to memory corruption issues. Mozilla fixed this vulnerability in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37 as part of a broader security update addressing multiple high-impact memory safety bugs. The vendor advisories confirm the fix and classify the impact as high. No known exploits have been reported in the wild.
Potential Impact
The vulnerability allows use-after-free conditions in the HTTP networking component, which can lead to memory corruption. Such memory safety issues may be leveraged to execute arbitrary code or cause application crashes. The impact is rated high by Mozilla, indicating significant security risk if exploited. However, no active exploitation has been observed.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. Users should update to these versions or later to remediate the issue. There are no indications that additional mitigations are required beyond applying the official patches.
CVE-2026-12291: Vulnerability in Mozilla Firefox
Description
CVE-2026-12291 is a use-after-free vulnerability in the Networking: HTTP component of Mozilla Firefox. This security flaw was addressed and fixed in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. The vulnerability is considered high impact due to the potential memory safety risks it poses. There are no known exploits in the wild at this time. Users of affected Firefox versions are advised to update to the fixed versions to mitigate the risk.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-12291 is a use-after-free vulnerability affecting the Networking: HTTP component in Mozilla Firefox. This type of vulnerability can lead to memory corruption issues. Mozilla fixed this vulnerability in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37 as part of a broader security update addressing multiple high-impact memory safety bugs. The vendor advisories confirm the fix and classify the impact as high. No known exploits have been reported in the wild.
Potential Impact
The vulnerability allows use-after-free conditions in the HTTP networking component, which can lead to memory corruption. Such memory safety issues may be leveraged to execute arbitrary code or cause application crashes. The impact is rated high by Mozilla, indicating significant security risk if exploited. However, no active exploitation has been observed.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 152, Firefox ESR 140.12, and Firefox ESR 115.37. Users should update to these versions or later to remediate the issue. There are no indications that additional mitigations are required beyond applying the official patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-06-15T15:08:06.495Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-57/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-58/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-59/","vendor":"Mozilla"}]
Threat ID: 6a314c7b0b89be6888b4cbb9
Added to database: 6/16/2026, 1:15:39 PM
Last enriched: 6/16/2026, 1:47:09 PM
Last updated: 6/17/2026, 5:02:47 AM
Views: 5
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