Firefox <149/ESR<140.9: Disability Access API UAF Sandbox Escape
CVE-2026-4688 Published on March 24, 2026
Sandbox escape due to use-after-free in the Disability Access APIs component
Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Vulnerability Analysis
CVE-2026-4688 is exploitable with network access, requires user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.
Weakness Types
What is a Dangling pointer Vulnerability?
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.
CVE-2026-4688 has been classified to as a Dangling pointer vulnerability or weakness.
What is a Dangling pointer Vulnerability?
The program dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid. When a program releases memory, but it maintains a pointer to that memory, then the memory might be re-allocated at a later time. If the original pointer is accessed to read or write data, then this could cause the program to read or modify data that is in use by a different function or process. Depending on how the newly-allocated memory is used, this could lead to a denial of service, information exposure, or code execution.
CVE-2026-4688 has been classified to as a Dangling pointer vulnerability or weakness.
Products Associated with CVE-2026-4688
You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-4688 are published in these products:
Affected Versions
Mozilla Firefox:- 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.