Firefox Canvas2D Incorrect Boundary Conditions ( Firefox 149 / ESR 140.9)
CVE-2026-4686 Published on March 24, 2026
Incorrect boundary conditions in the Graphics: Canvas2D component
Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Vulnerability Analysis
CVE-2026-4686 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Types
Improper Check for Unusual or Exceptional Conditions
The software does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the software.
What is a Memory Corruption Vulnerability?
The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.
CVE-2026-4686 has been classified to as a Memory Corruption vulnerability or weakness.
Products Associated with CVE-2026-4686
You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-4686 are published in these products:
Affected Versions
Mozilla Firefox:- Version 115.34, <= 115.* is unaffected.
- Version 140.9, <= 140.* is unaffected.
- Version 149, <= * is unaffected.
- Version 140.9, <= 140.* is unaffected.
- Version 149, <= * is unaffected.
- Version 0:140.9.0-1.el10_1 and below * is unaffected.
- Version 0:140.9.0-1.el10_1 and below * is unaffected.
- Version 0:140.9.0-1.el10_0 and below * is unaffected.
- Version 0:140.9.0-1.el10_0 and below * is unaffected.
- Version 0:140.9.0-1.el7_9 and below * is unaffected.
- Version 0:140.9.0-1.el8_10 and below * is unaffected.
- Version 0:140.9.0-1.el8_10 and below * is unaffected.
- Version 0:140.9.0-1.el8_2 and below * is unaffected.
- Version 0:140.9.0-1.el8_2 and below * is unaffected.
- Version 0:140.9.0-1.el8_4 and below * is unaffected.
- Version 0:140.9.0-1.el8_4 and below * is unaffected.
- Version 0:140.9.0-1.el8_4 and below * is unaffected.
- Version 0:140.9.0-1.el8_4 and below * is unaffected.
- Version 0:140.9.0-1.el8_6 and below * is unaffected.
- Version 0:140.9.0-1.el8_6 and below * is unaffected.
- Version 0:140.9.0-1.el8_6 and below * is unaffected.
- Version 0:140.9.0-1.el8_6 and below * is unaffected.
- Version 0:140.9.0-1.el8_6 and below * is unaffected.
- Version 0:140.9.0-1.el8_6 and below * is unaffected.
- Version 0:140.9.0-1.el8_8 and below * is unaffected.
- Version 0:140.9.0-1.el8_8 and below * is unaffected.
- Version 0:140.9.0-1.el8_8 and below * is unaffected.
- Version 0:140.9.0-1.el8_8 and below * is unaffected.
- Version 0:140.9.0-1.el9_7 and below * is unaffected.
- Version 0:140.9.0-1.el9_7 and below * is unaffected.
- Version 0:140.9.0-1.el9_0 and below * is unaffected.
- Version 0:140.9.0-1.el9_0 and below * is unaffected.
- Version 0:140.9.0-1.el9_2 and below * is unaffected.
- Version 0:140.9.0-1.el9_2 and below * is unaffected.
- Version 0:140.9.0-1.el9_4 and below * is unaffected.
- Version 0:140.9.0-1.el9_4 and below * is unaffected.
- Version 0:140.9.0-1.el9_6 and below * is unaffected.
- Version 0:140.9.0-1.el9_6 and below * is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.