MEDIUM
CVE-2026-8961
Published: May 19, 2026· Updated: May 20, 2026
6.5
CVSS v3.1
EPSS:0.03%probability of exploitation in 30 daysPercentile:9.2th
Official Description
Spoofing issue in the Form Autofill component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Technical Analysis
CVE-2026-8961 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 6.5.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Affected Vendors & Products
Mozilla2 products
firefoxthunderbird
Source: NVD CPE · 2 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (5)
→
https://bugzilla.mozilla.org/show_bug.cgi?id=1962625Permissions Required
→
https://www.mozilla.org/security/advisories/mfsa2026-46/Vendor Advisory
→
https://www.mozilla.org/security/advisories/mfsa2026-48/Vendor Advisory
→
https://www.mozilla.org/security/advisories/mfsa2026-50/Vendor Advisory
→
https://www.mozilla.org/security/advisories/mfsa2026-51/Vendor Advisory
Quick Facts
CVE IDCVE-2026-8961
CVSS Score6.5 / 10
SeverityMEDIUM
CISA KEVNo
EPSS (30d)0.03%
Affected1 vendor
PublishedMay 19, 2026
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-8961 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.