# CVE-2026-7258: PHP out-of-bounds read in urldecode leading to denial of service

Source: https://junglewise.ai/threats/cve-2026-7258-php-out-of-bounds-read-in-urldecode-leading-to-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-10. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-7258 · Severity: high · CVSS 7.5 · Published 2026-05-10

A vulnerability in the PHP programming language can allow an attacker to crash web applications or services. PHP is a widely used technology for building websites; an exploit could lead to a service outage, making a website unavailable to users. This issue specifically affects systems where PHP is running on certain operating systems like NetBSD.

Technologies: [PHP Group PHP](https://junglewise.ai/threats/technologies/php). Vendors: [PHP Group](https://junglewise.ai/threats/vendors/php-group).

## Quick answers

**Is CVE-2026-7258 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-7258 being exploited in the wild.

**How severe is CVE-2026-7258?** High severity, with a CVSS score of 7.5, published 10 May 2026.

**Which products and versions are affected?** PHP Group PHP 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.0 - 8.4.20, 8.5.0 - 8.5.5, 8.2.0 to 8.2.30, 8.3.0 to 8.3.30, 8.4.0 to 8.4.20, 8.5.0 to 8.5.5.

**Is there a fix for CVE-2026-7258?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-7258 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-7258?** Check whether you run PHP Group PHP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds read vulnerability exists in PHP's urldecode() and other functions due to the improper handling of signed characters when passed to ctype functions like isxdigit(). In the affected versions, characters are cast to signed integers, which can result in negative values being passed to ctype functions. On platforms that use optimized table-lookups for these functions (notably NetBSD), this causes a negative array offset access. An attacker can trigger this by providing specially crafted URL-encoded strings, leading to a segmentation fault and subsequent denial of service. The issue is resolved in PHP versions 8.2.31, 8.3.31, 8.4.21, and 8.5.6.

## Affected products

- PHP Group PHP 8.2.0 to 8.2.30, 8.3.0 to 8.3.30, 8.4.0 to 8.4.20, 8.5.0 to 8.5.5

## Timeline

- 2026-05-07: advisory: GitHub advisory published by PHP maintainers
- 2026-05-10: disclosed: CVE published to NVD

## References

- [https://github.com/php/php-src/security/advisories/GHSA-m8rr-4c36-8gq4](https://github.com/php/php-src/security/advisories/GHSA-m8rr-4c36-8gq4)

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