CVE-2026-54430

Server-Site Request Forgery in liboauth2

MEDIUM
5.1
CVSS Score
Published: July 2, 2026 at 10:30 AM UTC
Updated: October 25, 2026 at 09:10 PM UTC
1 product affected across 1 vendorLIBOAUTH2

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Severity
MEDIUM5.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

liboauth2 is vulnerable to Server-Side Request Forgery in oauth2_jose_jwks_aws_alb_resolve() function. The AWS ALB verifier reads both signer and kid from the unverified JWT header. If signer matches the configured ARN, kid is appended to alb_base_url without URL encoding or path sanitization, and the HTTP GET is issued before signature verification. This allows an attacker to force the server to send a GET request to an attacker-chosen internal path. This issue was fixed in version 2.3.0

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.3.0
Affected range stops below 2.3.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.1MEDIUMCERT-PL
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-918

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