CVE-2026-117990: Mozjs52 · Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 9.6 Critical.
Data as of 7 Nov 2026, 02:48 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 6 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 153.6, Thunderbird 159, or Thunderbird 153.6 or later versions where this vulnerability is patched. Applying these official updates will mitigate the risk of exploitation.
Description
CVE-2026-117990 is a critical vulnerability in the mozjs52 component related to incorrect boundary conditions in the Graphics: WebRender component. This flaw allows sandbox escape, potentially enabling an attacker to break out of restricted execution environments. The vulnerability was fixed in Firefox 159, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
References
- ubuntu.com/security/CVE-2026-117990 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-117990 (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=2079501 (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)