CVE-2026-17544Out-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.

8.1 HIGHEPSS 0.41%Not in KEVNVD: Analyzed

Last updated: 2026-10-23 22:10 UTC

OverviewCVSS details

8.1HIGHCVSS 4.0

Score source: php (CNA)
NVD status: Analyzed
Published: Jul 30, 2026
Assigner: php

Affected

PHP (PHP Group)

Versions: 8.4.x before 8.4.24 · 8.5.x before 8.5.9
Fixed in: 8.4.24, 8.5.9

Exploitation

Public exploit: None listed
CISA KEV: Not listed
KEV due date: —
SSVC: Exploitation none · Automatable yes · Impact total

EPSS · FIRST, scored Nov 8

0.41%chance of exploitation in 30 days

Higher than 36.35% of CVEs

CVSS 4.0 · php (CNA)

8.1High

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

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: None
User interaction: None
Confidentiality impact: High
Integrity impact: High
Availability impact: High
Confidentiality (other systems): None
Integrity (other systems): None
Availability (other systems): None

CVSS 3.1 · NVD

9.8Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

NVD status: Analyzed

Overview Affected Products References

NVD CVE.org

Overview

Severity

Score	Severity	Version	Vector String
8.1	HIGH	4.0php (CNA)	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
9.8	CRITICAL	3.1NVD	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CVE ID: CVE-2026-17544
Status: Analyzed
Assigner (CNA): php
Published: Jul 30, 2026
Last modified: 2026-10-23 22:10 UTC
Weaknesses: CWE-787 · Out-of-bounds write

Sources

Refreshed hourly from the sources above. Last fetched 2026-11-09 09:25 UTC.