CVE-2026-17544

CRITICAL
Published Jul 30, 2026 Modified Aug 5, 2026 CWE-787

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.

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CVSS v3.1 Score

9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0043
Probability of exploitation
0.35%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

Affected Products

Vendor Product
php php
php php

References

Frequently Asked Questions

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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).
How severe is CVE-2026-17544? +
CVE-2026-17544 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0043, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-17544? +
CVE-2026-17544 affects products from php, specifically: php. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-17544? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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