CVE-2026-117861: mozjs52 · Sandbox Escape
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 9.6 Critical.
Data as of 6 Nov 2026, 05:33 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 9.6 |
|---|
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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
This vulnerability has been fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation steps are required once the update is applied.
Description
CVE-2026-117861 is a critical vulnerability involving a sandbox escape in the DOM Navigation component. It affects multiple versions of the mozjs52 product and was fixed in Firefox 159 and Firefox ESR 153.6, as well as Thunderbird 159 and Thunderbird 153.6. The vulnerability allows an attacker to escape the sandbox environment, potentially leading to full compromise of confidentiality, integrity, and availability. The issue was publicly disclosed on October 27, 2026, with a high CVSS score of 9.6.
References
- ubuntu.com/security/CVE-2026-117861 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-117861 (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=2053240 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-118/ (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)