# CVE-2026-17544 — PHP

> As of 2026-07-31, CVE-2026-17544 is a High-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in PHP, CVSS v4.0 8.1, EPSS 0.4% (35.2th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-17544, most recently “Multiple Vulnerabilities in PHP (GovCERT.HK A26-07-52): Phar Symlink DoS, Bundled-libgd GIF Memory Corruption, pgsql SQL Injection, and BCMath Out-of-Bounds Write (CVE-2026-7260, CVE-2026-9672, CVE-2026-17543, CVE-2026-17544)”.

**Last updated:** 2026-07-31

## What is CVE-2026-17544?

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.

The record classifies CVE-2026-17544 under weakness class [CWE-787](https://intel.threadlinqs.com/cwe/CWE-787). 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 67 days ago.

## Severity and exploitation probability

- **CVSS v4.0 base score:** 8.1 — High (derived from score) (`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`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 35.2% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-30, last modified 2026-07-31

## Is CVE-2026-17544 being exploited?

No public exploitation evidence for CVE-2026-17544 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-07-31. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

## Affected products and versions

- [PHP Group](https://intel.threadlinqs.com/vendors/php-group): PHP

## How to fix CVE-2026-17544

No vendor patch reference has been recorded for CVE-2026-17544 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-17544

1 tracked threat in the Threadlinqs corpus references CVE-2026-17544, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Multiple Vulnerabilities in PHP (GovCERT.HK A26-07-52): Phar Symlink DoS, Bundled-libgd GIF Memory Corruption, pgsql SQL Injection, and BCMath Out-of-Bounds Write (CVE-2026-7260, CVE-2026-9672, CVE-2026-17543, CVE-2026-17544)](https://intel.threadlinqs.com/threat/TL-2026-1782) — HIGH · 2026-07-31

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-08-01. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com — vendor advisory](https://github.com/php/php-src/security/advisories/GHSA-x692-q9x7-8c3f)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-17544
Full detection coverage and IOCs for threats exploiting CVE-2026-17544 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp