CVE-2026-28695·PHP vulnerability

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 8% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Read the two together. CVE-2026-28695 scores 7.2 on CVSS, so a successful attack would be serious — but at <0.1%, almost nobody is currently attempting it. That is a different situation from a flaw under mass exploitation, and it is usually the difference between patching on your next maintenance window and patching tonight.

Affected versions

How to fix this CVE

Upgrade Craft CMS to version 5.9.0 or later to remediate this authenticated admin remote code execution vulnerability. The vulnerability exploits server-side template injection through the create() Twig function combined with Symfony's Process component, allowing attackers with admin credentials to execute arbitrary PHP code. Ensure all production instances are patched immediately as this bypasses protections from previous CVE-2025-57811 fixes.

sudo dnf update php

What an exploitation attempt looks like

Sample log line indicative of exploitation attempts:

POST requests to /admin URLs containing Twig template syntax with create() function calls, particularly payloads instantiating Symfony\Component\Process\Process class; example pattern: 'create("Symfony\\Component\\Process\\Process"' in request body or Twig template parameters

WAF mitigation (if patching is not yet possible)

Add this rule to your WAF to block exploitation attempts while you schedule the patch.

Implement WAF rules to block POST requests containing suspicious Twig template syntax patterns such as 'create(' followed by class paths, 'Process', or 'system' command execution patterns. Additionally, restrict access to /admin endpoints to known IP ranges and enforce strict Content-Type validation (application/json or application/x-www-form-urlencoded only).

How to check if you are affected

1. Run 'php -v' to identify the currently installed PHP version and confirm it is not running an outdated Craft CMS installation
2. Check Craft CMS installation at {CRAFT_ROOT}/craft.php and verify the version via 'php craft --version' or inspect config/general.php for the edition and version settings
3. Search web server logs (nginx: /var/log/nginx/access.log, Apache: /var/log/apache2/access.log) for POST requests to admin URLs containing 'twig', 'create(', or 'Process' keywords that may indicate exploitation attempts
4. Verify the patch by confirming Craft CMS version is >= 5.9.0 using 'php craft about' command or checking composer.lock for craftcms/cms package version

FAQ

Related PHP CVEs

References

• https://github.com/craftcms/cms/commit/e31e50849ad71638e11ea55fbd1ed90ae8f8f6e0
• https://github.com/craftcms/cms/security/advisories/GHSA-94rc-cqvm-m4pw