high CVSS 7.5

CVE-2026-7258·PHP vulnerability

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.

Severity
high
Software
PHP
Fixed in
8.5.6
Published
2026-05-10

Affected versions

From: 8.5.0

Until: 8.5.6

Fixed in: 8.5.6

How to fix this CVE

Update PHP immediately to version 8.5.6 or later to resolve a denial-of-service vulnerability affecting the urldecode() function and related ctype operations. This flaw can cause array access violations on systems with signed char defaults, resulting in application crashes. Verify your current PHP version and apply the security patch without delay.

sudo dnf update php-8.5.6 || sudo dnf upgrade php

Defensia detects this vulnerability

How to check if you are affected

  1. Run 'php -v' to check the currently installed PHP version and confirm it is below 8.5.6.
  2. Verify which PHP modules are loaded by running 'php -m' to assess if URL-related functions are actively used.
  3. Check application error logs in /var/log/php-fpm.log or /var/log/apache2/error.log for segmentation faults or array access warnings.
  4. After patching, re-run 'php -v' and confirm the version is 8.5.6 or higher, then restart PHP with 'sudo systemctl restart php-fpm' or equivalent.

FAQ

What is CVE-2026-7258?

CVE-2026-7258 is a denial-of-service vulnerability in PHP where the urldecode() function and related ctype operations pass signed characters to system functions that expect unsigned values. On systems with signed char defaults, this triggers negative array offsets, causing crashes and service unavailability.

Is CVE-2026-7258 being actively exploited?

No, this vulnerability is not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available. However, the DoS impact warrants immediate patching to prevent potential future exploitation.

What versions of PHP are affected by CVE-2026-7258?

PHP versions 8.5.0 through 8.5.5 are vulnerable. The vulnerability is fixed in PHP 8.5.6 and later. Earlier branch versions (8.2, 8.3, 8.4) have separate fixed versions in their respective patch releases.

How do I check if my server is vulnerable to CVE-2026-7258?

Run 'php -v' and check if your version falls between 8.5.0 and 8.5.5. If yes, your server is vulnerable and requires immediate upgrade to 8.5.6 or later.

Does Defensia detect CVE-2026-7258?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If PHP is installed on a monitored server, CVE-2026-7258 will appear in your dashboard with remediation steps.

Related PHP CVEs

CVE-2025-46348CVSS 10YesWiki is a wiki system written in PHP. Prior to version 4.5.4, the request to commence a site backup can be performed and downloaded without authentication. The archives are created with a predictable filename, so a malicious user could create and download an archive without being authenticated. This could result in a malicious attacker making numerous requests to create archives and fill up the file system, or by downloading the archive which contains sensitive site information. This issue has been patched in version 4.5.4.
CVE-2024-5932CVSS 10The GiveWP – Donation Plugin and Fundraising Platform plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.14.1 via deserialization of untrusted input from the 'give_title' parameter. This makes it possible for unauthenticated attackers to inject a PHP Object. The additional presence of a POP chain allows attackers to execute code remotely, and to delete arbitrary files.
CVE-2025-62521CVSS 10ChurchCRM is an open-source church management system. Prior to version 5.21.0, a pre-authentication remote code execution vulnerability in ChurchCRM's setup wizard allows unauthenticated attackers to inject arbitrary PHP code during the initial installation process, leading to complete server compromise. The vulnerability exists in `setup/routes/setup.php` where user input from the setup form is directly concatenated into a PHP configuration template without any validation or sanitization. Any parameter in the setup form can be used to inject PHP code that gets written to `Include/Config.php`, which is then executed on every page load. This is more severe than typical authenticated RCE vulnerabilities because it requires no credentials and affects the installation process that administrators must complete. Version 5.21.0 patches the issue.
CVE-2025-25174CVSS 10Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion') vulnerability in beeteam368 BeeTeam368 Extensions beeteam368-extensions allows PHP Local File Inclusion.This issue affects BeeTeam368 Extensions: from n/a through <= 1.9.4.
CVE-2025-47916CVSS 10Invision Community 5.0.0 before 5.0.7 allows remote code execution via crafted template strings to themeeditor.php. The issue lies within the themeeditor controller (file: /applications/core/modules/front/system/themeeditor.php), where a protected method named customCss can be invoked by unauthenticated users. This method passes the value of the content parameter to the Theme::makeProcessFunction() method; hence it is evaluated by the template engine. Accordingly, this can be exploited by unauthenticated attackers to inject and execute arbitrary PHP code by providing crafted template strings.

References

Track CVEs across your fleet automatically

Defensia scans your Linux servers and tells you exactly which ones are running vulnerable versions — including CVE-2026-7258. Free for 1 server.

Get started free