Improper check for unusual conditions in Mozilla Firefox
Priority LOW 39CWE-754Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 17 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
Incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0045 39th percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 140.9, 149Thunderbird (Mozilla): 140.9, 149Red Hat: 25 advisoriesRed Hat: 17 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Firefox | — | 140.9, 149 | Patch available | CNA |
| Mozilla | Thunderbird | — | 140.9, 149 | Patch available | CNA |
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 140.9, 149
- Fix · CNA Thunderbird (Mozilla) Fixed in 140.9, 149
Red Hat 25 advisories
- RHSA-2026:8850 Released 2026-04-20 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird-140.9.0-1.el8_4
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) thunderbird-140.9.0-1.el8_4
- RHSA-2026:8427 Released 2026-04-16 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux Server (v. 7 ELS) firefox-140.9.0-1.el7_9
- RHSA-2026:8315 Released 2026-04-15 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) thunderbird-140.9.0-1.el10_0
Show 22 more Red Hat advisories
- RHSA-2026:8290 Released 2026-04-15 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream EUS (v.9.4) thunderbird-140.9.0-1.el9_4
- RHSA-2026:8284 Released 2026-04-15 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) thunderbird-140.9.0-1.el9_6
- RHSA-2026:8289 Released 2026-04-15 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) thunderbird-140.9.0-1.el8_6
- Red Hat Enterprise Linux AppStream E4S (v.8.6) thunderbird-140.9.0-1.el8_6
- Red Hat Enterprise Linux AppStream TUS (v.8.6) thunderbird-140.9.0-1.el8_6
- RHSA-2026:8286 Released 2026-04-15 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v.9.0) thunderbird-140.9.0-1.el9_0
- RHSA-2026:8287 Released 2026-04-15 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) thunderbird-140.9.0-1.el9_2
- RHSA-2026:8288 Released 2026-04-15 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v.8.8) thunderbird-140.9.0-1.el8_8
- Red Hat Enterprise Linux AppStream TUS (v.8.8) thunderbird-140.9.0-1.el8_8
- RHSA-2026:8285 Released 2026-04-15 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream AUS (v. 8.2) thunderbird-140.9.0-1.el8_2
- RHSA-2026:7858 Released 2026-04-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-140.9.0-1.el8_4
- Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox-140.9.0-1.el8_4
- RHSA-2026:7837 Released 2026-04-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox-140.9.0-1.el9_6, firefox-x11-140.9.0-1.el9_6
- RHSA-2026:7845 Released 2026-04-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v.9.4) firefox-140.9.0-1.el9_4, firefox-x11-140.9.0-1.el9_4
- RHSA-2026:7838 Released 2026-04-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox-140.9.0-1.el8_8
- Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox-140.9.0-1.el8_8
- RHSA-2026:7843 Released 2026-04-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox-140.9.0-1.el10_0
- RHSA-2026:7842 Released 2026-04-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox-140.9.0-1.el8_6
- Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox-140.9.0-1.el8_6
- Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox-140.9.0-1.el8_6
- RHSA-2026:7841 Released 2026-04-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox-140.9.0-1.el9_2, firefox-x11-140.9.0-1.el9_2
- RHSA-2026:7839 Released 2026-04-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox-140.9.0-1.el9_0
- RHSA-2026:7840 Released 2026-04-13 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream AUS (v. 8.2) firefox-140.9.0-1.el8_2
- RHSA-2026:6917 Released 2026-04-07 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 8) thunderbird-140.9.0-1.el8_10
- RHSA-2026:6342 Released 2026-04-01 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 10) thunderbird-140.9.0-1.el10_1
- RHSA-2026:6188 Released 2026-03-30 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 9) thunderbird-140.9.0-1.el9_7
- RHSA-2026:5932 Released 2026-03-26 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-140.9.0-1.el8_10
- RHSA-2026:5930 Released 2026-03-26 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 9) firefox-140.9.0-1.el9_7, firefox-x11-140.9.0-1.el9_7
- RHSA-2026:5931 Released 2026-03-26 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 10) firefox-140.9.0-1.el10_1
Vendor assessments
Red Hat
Red Hat rating: Moderate. 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-2026:5931, RHSA-2026:6342 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:5932, RHSA-2026:6917 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:5930, RHSA-2026:6188 |
| Red Hat Enterprise Linux AppStream AUS (v. 8.2) | Fixed | RHSA-2026:7840, RHSA-2026:8285 |
| Red Hat Enterprise Linux AppStream AUS (v.8.4) | Fixed | RHSA-2026:7858, RHSA-2026:8850 |
| Red Hat Enterprise Linux AppStream AUS (v.8.6) | Fixed | RHSA-2026:7842, RHSA-2026:8289 |
| Red Hat Enterprise Linux AppStream E4S (v.8.6) | Fixed | RHSA-2026:7842, RHSA-2026:8289 |
| Red Hat Enterprise Linux AppStream E4S (v.8.8) | Fixed | RHSA-2026:7838, RHSA-2026:8288 |
| Red Hat Enterprise Linux AppStream E4S (v.9.0) | Fixed | RHSA-2026:7839, RHSA-2026:8286 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:7841, RHSA-2026:8287 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:7843, RHSA-2026:8315 |
| Red Hat Enterprise Linux AppStream EUS (v.9.4) | Fixed | RHSA-2026:7845, RHSA-2026:8290 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:7837, RHSA-2026:8284 |
| Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) | Fixed | RHSA-2026:7858, RHSA-2026:8850 |
| Red Hat Enterprise Linux AppStream TUS (v.8.6) | Fixed | RHSA-2026:7842, RHSA-2026:8289 |
| Red Hat Enterprise Linux AppStream TUS (v.8.8) | Fixed | RHSA-2026:7838, RHSA-2026:8288 |
| Red Hat Enterprise Linux Server (v. 7 ELS) | Fixed | RHSA-2026:8427 |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-4713
- 2026-10-03 Alias added: GHSA-954r-qq48-9vr2
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-2026-4713 · CVE Program
- CVE-2026-4713 · NVD
- FIRST EPSS
- GHSA-954r-qq48-9vr2 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-4713 · 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