CVE-2026-8975

HIGH 8.8

Memory safety bugs fixed in Firefox ESR 115.36, Firefox ESR 140.11 and Firefox 151

CVSS Score

8.8

EPSS Score

0.0%

EPSS Percentile

0th

Memory safety bugs present in Firefox ESR 115.35, Firefox ESR 140.10 and Firefox 150. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Vendor	mozilla
Product	firefox
Ecosystems	Browser JavaScript
Industries	Technology
Published	May 19, 2026
Last Updated	Jun 30, 2026

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Affected Versions

Mozilla / Firefox

All versions affected

Mozilla / Thunderbird

All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗

bugzilla.mozilla.org: https://bugzilla.mozilla.org/buglist.cgi?bug_id=1860195%2C2029325%2C2029429%2C2029910%2C2035915%2C2038678%2C2038669 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-46/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-47/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-48/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-50/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-51/ access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-8975 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2479840 security.access.redhat.com: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8975.json access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26551 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:27715 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26539 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:21380 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:22325 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:21382 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:22643 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26629 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26270 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26606 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26536 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26630 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26268 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26491 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26269 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26493 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26174 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26492 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:26521 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:21378 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:21381

Credits

Andrew McCreight, Valentin Gosu, Nika Layzell, Tom Schuster and the Mozilla Fuzzing Team