CVE-2026-92074
HIGH 8.8 ALL-YEARSMitigation bypass in the Popup Blocker component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.
ELEVATED IMPACT
Severe if exploited (CVSS 8.8), but no confirmed exploitation. Patch on a normal cadence.
Exploitation likelihood
0.1%chance of exploitation in 30 days · 1st percentile
○ In CISA KEV○ Public exploit / PoC◆ SSVC: exploitation none, automatable no
Impact if exploited
8.8CVSS 3.1 · HIGH · ADP
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓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-693: Protection Mechanism Failure
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/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
- HIGH 8.8 v3.1 · ADP Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - HIGH 8.8 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H