CVE-2026-117887: Use-after-free in the DOM · Core & HTML component
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 6 Nov 2026, 05:20 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 8.8 |
|---|
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSmozjs102pkg:deb/ubuntu/mozjs102?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSmozjs115pkg:deb/ubuntu/mozjs115?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmozjs102pkg:deb/ubuntu/mozjs102?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmozjs78pkg:deb/ubuntu/mozjs78?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmozjs91pkg:deb/ubuntu/mozjs91?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSthunderbirdpkg:deb/ubuntu/thunderbird?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available and users should upgrade to Firefox 159, Firefox ESR 115.44 or 153.6, Thunderbird 159, or Thunderbird 153.6 to remediate this vulnerability. Applying these official updates fully mitigates the risk. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-117887 is a use-after-free vulnerability in the DOM Core and HTML components of Mozilla products. It was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6. The vulnerability has a high severity with a CVSS score of 8.8, indicating it can lead to significant impact on confidentiality, integrity, and availability. No known exploits in the wild have been reported. Users are advised to update to the fixed versions to mitigate the risk.
References
- ubuntu.com/security/CVE-2026-117887 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-117887 (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-118/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-120/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-122/ (opens in a new tab)
- bugzilla.mozilla.org/show_bug.cgi?id=2077385 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-118/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-119/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-120/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-121/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-122/ (opens in a new tab)