Vulnerability · CVE-2026-100818
Security Vulnerabilities fixed in Firefox ESR 140.17 — Mozilla
Published Unknown date · Mozilla
Check if you run it
No confirmed exploitation is on record for CVE-2026-100818. EPSS is 0.26%. Act only if a listed version of Mozilla is installed.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.26%
- Remediation
- Not established
- Affected products
- Mozilla
Security Vulnerabilities fixed in Firefox ESR 140.17 — Mozilla
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-100818
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
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-2026-100818. EPSS is 0.26%. Act only if a listed version of Mozilla 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?
No weakness class is stored. EPSS 0.26%. 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.
Oct 17, 2026 · Mozilla Security Advisories
Detected
Security Vulnerabilities fixed in Firefox ESR 140.17 — Mozilla
Sources
- CVE.orgVulnerability recordCVE-2026-100818
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-100818
30-day exploitation probability 0.3%
first.org - Mozilla Security AdvisoriesVendor advisoryCVE-2026-100818
Security Vulnerabilities fixed in Thunderbird 153.4 — Mozilla
mozilla.org
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.