High 8.1Published Sep 29, 2026

CVE-2026-100830Mitigation bypass in the DOM: Navigation component

Updated under an hour ago (Oct 26, 2026, 2:20 PM ET)

Does this affect you?

It affects Mozilla Firefox and 1 other product. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.15%, higher than 4% of scored CVEs.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for Mozilla Firefox

Exploited in the last 30 days

Mitigation bypass in the DOM: Navigation component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 153.4, and Firefox 157.

CVSS: 8.1 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Weakness (CWE): CWE-346
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.15% (percentile 4)
Assigned by: mozilla
NVD analysis: Analyzed
Record last updated: Oct 1, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Mozilla Firefox mozilla:firefox (from the name)	153.4 builds before 153.* not affected; from 157 not affected	CNA record
Mozilla Thunderbird mozilla:thunderbird (from the name)	153.4 builds before 153.* not affected; from 157 not affected	CNA record
mozilla firefox mozilla:firefox	before 153.4.0; from 154.0.0 before 157.0.0	NVD
mozilla thunderbird mozilla:thunderbird	before 153.4.0; from 154.0 before 157.0	NVD

References

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2066770	permissions-required
https://www.mozilla.org/security/advisories/mfsa2026-100/	vendor-advisory
https://www.mozilla.org/security/advisories/mfsa2026-101/	vendor-advisory
https://www.mozilla.org/security/advisories/mfsa2026-103/	vendor-advisory
https://www.mozilla.org/security/advisories/mfsa2026-97/	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.