CVE-2026-92048
CRITICAL 9 ALL-YEARSSandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
ELEVATED IMPACT
Severe if exploited (CVSS 9), but no confirmed exploitation. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 19th percentile
○ In CISA KEV○ Public exploit / PoC◆ SSVC: exploitation none, automatable no
Impact if exploited
9CVSS 3.1 · CRITICAL · ADP
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ⚠User interaction: A user must take an action (click / open a file)
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
No public exploit or proof-of-concept code is catalogued for this CVE (no ExploitDB, Nuclei, or CISA-KEV entry). It may still exist — search GitHub or check the references below.
Weakness (CWE)
- CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Mozilla | Firefox | < 153.3.0 |
| Mozilla | Firefox | ≥ 154.0.0 and < 156.0.0 |
| Mozilla | Thunderbird | < 153.3.0 |
| Mozilla | Thunderbird | ≥ 154.0 and < 156.0 |
All CVSS metrics
- CRITICAL 9 v3.1 · ADP Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H - CRITICAL 9 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H