CVE-2026-56706: Adminer before 5.4.3 CSRF Token Secret Recovery via XOR Masking

Severity: medium (CVSS 6.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-25 · updated 2026-10-12
Weakness: CWE-330

Description

Adminer before 5.4.3 uses a CSRF token scheme that transmits both the XOR mask and the masked value in every token (format (rand XOR secret):rand), allowing anyone who observes a single CSRF token (e.g., via network sniffing, log files, Referrer header, or XSS) to recover the session secret with a single XOR operation and forge unlimited valid tokens. The implementation is further weakened by a low-entropy session token (rand(1,1e6), ~20 bits) that permits blind brute-force, and by use of loose comparison (==) in token verification, enabling PHP type juggling. Exploitation enables cross-site request forgery against authenticated sessions, including execution of arbitrary SQL queries.

Affected products

vrana adminer: before 5.4.3 — fixed in 5.4.3

How to fix

Upgrade to a fixed version: vrana adminer 5.4.3. Check the vendor advisory for mitigations.

References

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