Out-of-bounds Read in PHP

CVE-2026-7568

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, the metaphone() function in ext/standard/metaphone.c uses a signed int variable to track the current position within the input string. If a string longer than 2,147,483,647 bytes is passed, a signed integer overflow occurs, resulting in undefined behavior. This can lead to an out-of-bounds read, causing a segmentation fault or access to unrelated memory, and may affect the availability of the PHP process.

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: 0.008 (56.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-7568: held from 0.005 to 0.008.

EPSS over last 30 days · oldest: 0.005 · newest: 0.008 · change: +0.004

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-7568?
CVE-2026-7568 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-2026-7568?
High severity. CVSS v3 base score is 7.5 out of 10.