Out-of-bounds Read in PHP
CVE-2026-7258
In PHP versions 8.2.* before 8.2.31, 8.3.* before 8.3.31, 8.4.* before 8.4.21, and 8.5.* before 8.5.6, some functions, including urldecode(), pass signed char to ctype functions (like isxdigit()). On the systems with default signed char and optimized table-lookup ctype functions - such as NetBSD - this can lead to accessing array with negative offset, which can trigger a denial of service.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (32.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/php/php-src/security/advisories/GHSA-m8rr-4c36-8gq4 (vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-7258?
- CVE-2026-7258 is a high-severity vulnerability in PHP, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-05-10.
- How severe is CVE-2026-7258?
- High severity. CVSS v3 base score is 7.5 out of 10.