Bug 2509256 (CVE-2026-17544)

Summary: CVE-2026-17544 php: PHP: Arbitrary code execution via out-of-bounds write in bccomp()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: rcollet, rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in PHP. A remote attacker could exploit this vulnerability by providing specially crafted inputs to the `bccomp()` function. This could lead to an out-of-bounds write, resulting in stack and heap corruption. Such memory corruption can enable arbitrary code execution, allowing the attacker to take control of the affected system.
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Bug Depends On: 2511423    
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Description OSIDB Bzimport 2026-07-30 12:01:12 UTC 
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.
Comment 1 Remi Collet 2026-07-31 12:31:13 UTC 
Notice: Versions < 8.4 are not affected
Comment 3 errata-xmlrpc 2026-08-19 14:18:06 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:56969 https://access.redhat.com/errata/RHSA-2026:56969