MEDIUM
CVE-2026-8391
Published: May 12, 2026· Updated: May 13, 2026
5.3
CVSS v3.1
EPSS:0.02%probability of exploitation in 30 daysPercentile:5.1th
Official Description
Other issue in the JavaScript Engine component. This vulnerability was fixed in Firefox 150.0.3.
Technical Analysis
CVE-2026-8391 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Affected Vendors & Products
Mozilla1 product
firefox
Source: NVD CPE · 1 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 (2)
→
https://bugzilla.mozilla.org/show_bug.cgi?id=2038575Permissions Required
→
https://www.mozilla.org/security/advisories/mfsa2026-45/Vendor Advisory
Quick Facts
CVE IDCVE-2026-8391
CVSS Score5.3 / 10
SeverityMEDIUM
CISA KEVNo
EPSS (30d)0.02%
Affected1 vendor
PublishedMay 12, 2026
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-8391 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.