5.1

CVE-2026-54430: openidc liboauth2 Server-Side Request Forgery (SSRF)

CVSS: 5.1v4.0MediumDeferred
AliasesUBUNTU-CVE-2026-54430DEBIAN-CVE-2026-54430
Published 02-07-2026Last modified 02-07-2026
Open JSON

Vulnerability summary

CVE-2026-54430 is a medium (CVSS 5.1) Server-Side Request Forgery (SSRF) vulnerability in openidc liboauth2. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 5.8% of scored vulnerabilities.

Overall risk
20/100
0100
Low · default modelHow is this calculated?
CVSS score
5.1/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.17%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 02-07-2026
    PublishedVulnerability first disclosed.
  2. 02-07-2026
    Last modifiedVulnerability information updated.

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

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

6%

Versus all other CVEs

30-day change

0.00 pp

From 0.17% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.17%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • liboauth2All versions (No fix recorded) | < 2.3.0-1
Openidc1 product
Ubuntu1 product
  • liboauth2All versions (No fix recorded)

3 vendors · 3 products

References

6 links