5.1
MEDIUM CVSS 4.0
CVE-2026-54430
Server-Site Request Forgery in liboauth2
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

INFO

Published Date :

July 2, 2026, 11:16 a.m.

Last Modified :

July 2, 2026, 5:43 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-54430 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 4.0 MEDIUM 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6
CVSS 4.0 MEDIUM [email protected]
Solution
Update liboauth2 to version 2.3.0 or later to fix SSRF vulnerability.
  • Update liboauth2 to version 2.3.0 or later.
  • Validate JWT header before making HTTP requests.
Public PoC/Exploit Available at Github

CVE-2026-54430 has a 1 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-54430.

URL Resource
https://cert.pl/en/posts/2026/07/CVE-2026-54430
https://github.com/OpenIDC/liboauth2
https://github.com/OpenIDC/liboauth2/commit/347507ac5b51f48c2933bbe49b2ee07c2af4712b
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-54430 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-54430 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

CVEs, conference materials, research.

Updated: 2 weeks, 5 days ago
8 stars 0 fork 0 watcher
Born at : May 28, 2020, 11:37 a.m. This repo has been linked 186 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-54430 vulnerability anywhere in the article.

  • cert.pl
Vulnerabilities in OpenIDC liboauth2 software

Vulnerabilities in OpenIDC liboauth2 software CVE ID CVE-2026-54430 Publication date 02 July 2026 Vendor OpenIDC Product liboauth2 Vulnerable versions All before 2.3.0 Vulnerability type (CWE) Server- ... Read more

Published Date: Jul 02, 2026 (1 month ago)

The following table lists the changes that have been made to the CVE-2026-54430 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 02, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-54430', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-02T12:17:15.414798Z'}
  • CVE Modified by [email protected]

    Jul. 02, 2026

    Action Type Old Value New Value
    Added Reference https://cert.pl/en/posts/2026/07/CVE-2026-54430
    Removed Reference https://cert.pl/en/posts/2026/06/CVE-2026-54430
  • New CVE Received by [email protected]

    Jul. 02, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/OpenIDC/liboauth2', 'vendor': 'OpenIDC', 'modules': ['oauth2_jose_jwks_aws_alb_resolve()'], 'product': 'liboauth2', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '2.3.0', 'versionType': 'semver'}], 'programFiles': ['src/jose.c'], 'defaultStatus': 'unaffected'}]
    Added 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
    Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-918
    Added Reference https://cert.pl/en/posts/2026/06/CVE-2026-54430
    Added Reference https://github.com/OpenIDC/liboauth2
    Added Reference https://github.com/OpenIDC/liboauth2/commit/347507ac5b51f48c2933bbe49b2ee07c2af4712b
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.