Cookie Injection Vulnerability in Adminer Affects Multiple Versions
CVE-2026-63771

6MEDIUM

Key Information:

Vendor

Vrana

Status
Adminer
Vendor
CVE Published:
20 July 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-63771?

The vulnerability in Adminer, found in versions prior to 5.4.3, arises from the improper handling of cookie attributes via the unsanitized X-Forwarded-Prefix HTTP header. This flaw enables attackers to manipulate the Set-Cookie path attributes, thereby downgrading SameSite protections. When a reverse proxy is misconfigured, attackers can exploit this vulnerability to bypass cookie security measures and initiate cross-origin authenticated requests, posing significant risks to users and their data.

Affected Version(s)

adminer 0 < 5.4.3

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-63771 - Proof of Concept

References

https://github.com/vrana/adminer/issues/1298
technical-descriptionexploit
https://github.com/vrana/adminer/security/advisories/GHSA...
vendor-advisory
https://github.com/vrana/adminer/releases#release-v5.4.3
release-notes

CVSS V4

Score:
6
Severity:
MEDIUM
Confidentiality:
High
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

George Chen
.