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OpenAdvisories
High · 8.1 Public exploit CVE-2026-17544 EUVD-2026-51091

Out-of-bounds write in bccomp() via crafted operand and scale

Published Jul 30, 2026 · Updated Jul 31, 2026 · Assigned by php

Vendor: PHP Group Product: PHP Package: php8.4 Package: php8.5 Package: php84 Package: php85 Ecosystem: Alpine Ecosystem: Debian Ecosystem: Ubuntu

Description

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.

Affected products

VendorProductAffectedFixed
PHP Group PHP 8.4.* – < 8.4.24, 8.5.* – < 8.5.9 8.4.24

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Debian

Security tracker ↗
ReleasePackageFixed inAdvisory
Debian 14 php8.4 8.4.24-1 —
Debian 13 php8.4 8.4.24-1~deb13u1 —

Ubuntu

Security tracker ↗
ReleasePackageFixed inAdvisory
Ubuntu 26.04 LTS php8.5 8.5.4-0ubuntu1.3 USN-8743-1
Ubuntu 24.04 LTS php8.3 8.3.6-0ubuntu0.24.04.11 USN-8743-1
Ubuntu 22.04 LTS php8.1 8.1.2-1ubuntu2.26 USN-8743-1

Red Hat

Security tracker ↗
ReleasePackageFixed inAdvisory
RHEL 10 php8.4 +23 8.4.24-1.el10_2 RHSA-2026:56969
Show 1 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Red Hat Hardened Images 1 php +26 8.5.9-1.hum1 RHSA-2026:47200

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 10 php8.4 +23 8.4.24-1.el10_2 ALSA-2026:56969

Rocky Linux

Errata ↗
ReleasePackageFixed inAdvisory
Rocky Linux 10 php8.4 8.4.24-1.el10_2 RLSA-2026:56969

SUSE

Security tracker ↗
ReleasePackageFixed inAdvisory
SLES 15 SP7 php8 +5 8.3.33-150700.3.18.1 SUSE-SU-2026:3509-1
Show 2 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 php8 +4 8.4.24-160000.1.1 SUSE-SU-2026:23144-1, SUSE-SU-2026:23121-1
SLES 16.0 php8 +4 8.4.24-160000.1.1 SUSE-SU-2026:23144-1, SUSE-SU-2026:23121-1

openSUSE

Security tracker ↗
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed php8 8.5.9-1.1 openSUSE-SU-2026:11418-1
openSUSE Leap 16.0 php8 +5 8.4.24-160000.1.1 openSUSE-SU-2026:21532-1

Alpine

Security tracker ↗
ReleasePackageFixed inAdvisory
Alpine v3.24 php84 8.4.24-r0 —
Alpine v3.24 php85 8.5.9-r0 —
Alpine v3.23 php84 8.4.27-r0 —
Alpine v3.23 php85 8.5.12-r0 —
Alpine v3.22 php84 8.4.27-r0 —

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 php8.4 +27 8.4.24-1.amzn2023.0.1 ALAS2023-2026-2042
Amazon Linux 2023 php8.5 +26 8.5.9-1.amzn2023.0.1 ALAS2023-2026-2041

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 10 php8.4 +23 8.4.24-1.el10_2 ELSA-2026-56969

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 2 repositories

  • Boreas37/CVE-2026-17544-PoC ★ 6 · Aug 12, 2026

    CVE-2026-17544 — PHP bcmath bccomp() OOB write (stack smashing). Verified: crash on 8.4.23/8.5.8, fixed in 8.4.24. GHSA-x692-q9x7-8c3f

  • r2qa/CVE-2026-17544 ★ 0 · Aug 15, 2026

    CVE-2026-17544: PHP bcmath OOB write → universal memory-only RCE & disable_functions/open_basedir bypass. Offset-free runtime resolver. Verified on PHP 8.4.x / 8.5.x.

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 16

References