PHP bccomp OOB Write in ext-bcmath 8.4.x/8.5.x before 8.4.24/8.5.9
CVE-2026-17544 Published on July 30, 2026
Out-of-bounds write in bccomp() via crafted operand and scale
Attacker-provided inputs to bccomp() could lead to an out-of-bounds write with stack and heap corruption in PHP versions from 8.4.* before 8.4.24 and from 8.5.* before 8.5.9.
Vulnerability Analysis
CVE-2026-17544 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 availability.
Weakness Type
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-2026-17544 has been classified to as a Memory Corruption vulnerability or weakness.
Products Associated with CVE-2026-17544
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Affected Versions
PHP Group PHP:- Version 8.4.* and below 8.4.24 is affected.
- Version 8.5.* and below 8.5.9 is affected.