CVE-2026-17544

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

At a glance

Severity: HIGH 8.1
EPSS: EPSS 0.42 % · percentile 36 (2026-10-27)
State: PUBLISHED
Published: 2026-07-30
Updated: 2026-07-31
Assigner: php
NVD status: Analyzed

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.

Scores

Version	Score	Vector	Scored by
CVSS 4.0	HIGH 8.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/AU:N	php
CVSS 4.0	HIGH 8.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:X/V:X/RE:X/U:X	NVD · security@php.net (Secondary)
CVSS 3.1	CRITICAL 9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	NVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

CWE-787

European references

ENISA EUVD · EUVD-2026-51091
GCVE · GCVE-0-2026-17544

CERT-FR advisories

CERTFR-2026-AVI-0952 — Multiples vulnérabilités dans PHP · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

cpe:2.3:a:php:php:*:*:*:*:*:*:*:* ≥ 8.4.0 < 8.4.24
cpe:2.3:a:php:php:*:*:*:*:*:*:*:* ≥ 8.5.0 < 8.5.9

Affected products

Product	Versions
PHP Group · PHP	affected 8.4.* < 8.4.24 ; affected 8.5.* < 8.5.9

References

https://github.com/php/php-src/security/advisories/GHSA-x692-q9x7-8c3f

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD