Vulnerability · CVE-2026-8955
Privilege escalation in the DOM: Workers component.
Published May 19, 2026 · catalog updated Oct 14, 2026 · Privilege escalation in the
Check if you run it
No confirmed exploitation is on record for CVE-2026-8955. EPSS is 0.41%. Act only if a listed version of Privilege escalation in the is installed.
- Severity
- High8.8
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.41%
- Remediation
- Advisory link
- Affected products
- cpe mozilla/firefox · cpe mozilla/thunderbird
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe mozilla/firefoxversion unspecified
- cpe mozilla/thunderbirdversion unspecified
How to fix CVE-2026-8955
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-8955. EPSS is 0.41%. Act only if a listed version of Privilege escalation in the is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-269: Improper Privilege Management. EPSS 0.41%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
May 19, 2026 · NIST NVD
Detected
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Oct 14, 2026 · NIST NVD
Updated
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Sources
- CVE.orgVulnerability recordCVE-2026-8955
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-8955
30-day exploitation probability 0.4%
first.org - NIST NVDVulnerability recordCVE-2026-8955
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.