Mozilla Foundation Security Advisory 2025-57
Security Vulnerabilities fixed in Firefox ESR 115.26
- Announced
- July 22, 2025
- Impact
- high
- Products
- Firefox ESR
- Fixed in
-
- Firefox ESR 115.26
#CVE-2025-8027: JavaScript engine only wrote partial return value to stack
- Reporter
- Nan Wang
- Impact
- high
Description
On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits.
References
#CVE-2025-8028: Large branch table could lead to truncated instruction
- Reporter
- Gary Kwong
- Impact
- high
Description
On arm64, a WASM br_table instruction with a lot of entries could lead to the label being too far from the instruction causing truncation and incorrect computation of the branch address.
References
#CVE-2025-8033: Incorrect JavaScript state machine for generators
- Reporter
- Shaheen Fazim
- Impact
- low
Description
The JavaScript engine did not handle closed generators correctly and it was possible to resume them leading to a nullptr deref.
References
#CVE-2025-8034: Memory safety bugs fixed in Firefox ESR 115.26, Firefox ESR 128.13, Thunderbird ESR 128.13, Firefox ESR 140.1, Thunderbird ESR 140.1, Firefox 141 and Thunderbird 141
- Reporter
- the Mozilla Fuzzing Team
- Impact
- high
Description
Memory safety bugs present in Firefox ESR 115.25, Firefox ESR 128.12, Thunderbird ESR 128.12, Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140. 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.