Memory corruption in Mozilla Firefox
Priority LOW 30CWE-119Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Partial Red Hat: 14 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-79.
Summary
Other issue in the JavaScript Engine component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00298 22nd percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 115.36, 140.11, 150.0.3Thunderbird (Mozilla): 140.11Red Hat: 21 advisoriesRed Hat: 14 fixed, 3 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 115.36, 140.11, 150.0.3
- Fix · CNA Thunderbird (Mozilla) Fixed in 140.11
Red Hat 21 advisories
- RHSA-2026:27715 Released 2026-06-22 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox-140.11.0-1.el10_0
- RHSA-2026:26630 Released 2026-06-17 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox-140.11.0-1.el8_8
- Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox-140.11.0-1.el8_8
- RHSA-2026:26629 Released 2026-06-17 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-140.11.0-1.el8_4
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox-140.11.0-1.el8_4
Show 18 more Red Hat advisories
- RHSA-2026:26606 Released 2026-06-17 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox-140.11.0-1.el8_6
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) firefox-140.11.0-1.el8_6
- RHSA-2026:26551 Released 2026-06-17 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux Server (v. 7 ELS) firefox-140.11.0-1.el7_9
- RHSA-2026:26539 Released 2026-06-17 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) thunderbird-140.11.0-1.el10_0
- RHSA-2026:26536 Released 2026-06-17 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) thunderbird-140.11.0-1.el8_6
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) thunderbird-140.11.0-1.el8_6
- RHSA-2026:26521 Released 2026-06-17 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) thunderbird-140.11.0-1.el9_6
- RHSA-2026:26492 Released 2026-06-17 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox-140.11.0-1.el9_6, firefox-x11-140.11.0-1.el9_6
- RHSA-2026:26493 Released 2026-06-17 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) firefox-140.11.0-1.el9_4, firefox-x11-140.11.0-1.el9_4
- RHSA-2026:26491 Released 2026-06-17 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox-140.11.0-1.el9_2, firefox-x11-140.11.0-1.el9_2
- RHSA-2026:26268 Released 2026-06-16 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v.8.8) thunderbird-140.11.0-1.el8_8
- Red Hat Enterprise Linux AppStream TUS (v.8.8) thunderbird-140.11.0-1.el8_8
- RHSA-2026:26269 Released 2026-06-16 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) thunderbird-140.11.0-1.el9_2
- RHSA-2026:26270 Released 2026-06-16 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird-140.11.0-1.el8_4
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) thunderbird-140.11.0-1.el8_4
- RHSA-2026:26174 Released 2026-06-16 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) thunderbird-140.11.0-1.el9_4
- RHSA-2026:22643 Released 2026-06-03 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 8) thunderbird-140.11.0-1.el8_10
- RHSA-2026:22325 Released 2026-06-01 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 10) thunderbird-140.11.0-1.el10_2
- RHSA-2026:21378 Released 2026-05-27 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 9) firefox-140.11.0-1.el9_8, firefox-x11-140.11.0-1.el9_8
- RHSA-2026:21381 Released 2026-05-27 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 9) thunderbird-140.11.0-1.el9_8
- RHSA-2026:21380 Released 2026-05-27 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 10) firefox-140.11.0-1.el10_2
- RHSA-2026:21382 Released 2026-05-27 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-140.11.0-1.el8_10
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:21380, RHSA-2026:22325 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:21382, RHSA-2026:22643 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:21378, RHSA-2026:21381 |
| Red Hat Enterprise Linux AppStream AUS (v.8.4) | Fixed | RHSA-2026:26270, RHSA-2026:26629 |
| Red Hat Enterprise Linux AppStream AUS (v.8.6) | Fixed | RHSA-2026:26536, RHSA-2026:26606 |
| Red Hat Enterprise Linux AppStream E4S (v.8.8) | Fixed | RHSA-2026:26268, RHSA-2026:26630 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:26269, RHSA-2026:26491 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:26174, RHSA-2026:26493 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:26539, RHSA-2026:27715 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:26492, RHSA-2026:26521 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) | Fixed | RHSA-2026:26270, RHSA-2026:26629 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) | Fixed | RHSA-2026:26536, RHSA-2026:26606 |
| Red Hat Enterprise Linux AppStream TUS (v.8.8) | Fixed | RHSA-2026:26268, RHSA-2026:26630 |
| Red Hat Enterprise Linux Server (v. 7 ELS) | Fixed | RHSA-2026:26551 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-8391
- 2026-10-03 Alias added: GHSA-93pv-vhrf-wv64
References
More Mozilla Firefox vulnerabilities
- TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
- TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
- TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
- TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
- TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2026-8391 · CVE Program
- CVE-2026-8391 · NVD
- FIRST EPSS
- GHSA-93pv-vhrf-wv64 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-8391 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences