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TI-2021-20310 Aliases CVE-2021-44878GHSA-xhw6-hjc9-679m

If an OpenID Connect provider supports the "none" algorithm (i.e., tokens with no…

Priority LOW 35CWE-347Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-347.

Summary

If an OpenID Connect provider supports the "none" algorithm (i.e., tokens with no signature), pac4j v5.3.0 (and prior) does not refuse it without an explicit configuration on its side or for the "idtoken" response type which is not secure and violates the OpenID Core Specification. The "none" algorithm does not require any signature verification when validating the ID tokens, which allows the attacker to bypass the token validation by injecting a malformed ID token using "none" as the value of "alg" key in the header with an empty signature value.

Why it matters now

EPSS 0.00925 60th percentileScored 2026-11-07
Fix Fixed org.pac4j:pac4j-oidc (Maven): 4.5.5, 5.3.1

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
—org.pac4j:pac4j-oidc (Maven)before 4.5.54.5.5Patch availableGHSA-xhw6-hjc9-679m
—org.pac4j:pac4j-oidc (Maven)5.0 to before 5.3.15.3.1Patch availableGHSA-xhw6-hjc9-679m
  • — Vendor— Affected all versions Fixed in — No fix listed CNA
  • org.pac4j:pac4j-oidc (Maven) Vendor— Affected before 4.5.5 Fixed in 4.5.5 Patch available GHSA-xhw6-hjc9-679m
  • org.pac4j:pac4j-oidc (Maven) Vendor— Affected 5.0 to before 5.3.1 Fixed in 5.3.1 Patch available GHSA-xhw6-hjc9-679m

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:pac4j:pac4j:*:*:*:*:*:*:*:*before 4.5.5; 5.0.0 to before 5.3.1Vulnerablepac4j
  • cpe:2.3:a:pac4j:pac4j:*:*:*:*:*:*:*:* Versions before 4.5.5; 5.0.0 to before 5.3.1 Vulnerable ·pac4j

Remediation

  • Fix · GHSA-xhw6-hjc9-679m org.pac4j:pac4j-oidc (Maven) Fixed in 4.5.5 Advisory →
  • Fix · GHSA-xhw6-hjc9-679m org.pac4j:pac4j-oidc (Maven) Fixed in 5.3.1 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-44878
  2. 2026-10-03 Alias added: GHSA-xhw6-hjc9-679m

References

Patch 1

Advisory 3

Other 4

  • TI-2026-29211 LDAP Injection in PAC4J CVSS 4.0HIGH 8.7
  • TI-2026-29210 Cross-Site Request Forgery in PAC4J CVSS 4.0HIGH 7.0
  • TI-2019-08020 The SAML identifier generated within SAML2Utils.java was found to make use of the apache… CVSS 3.1MEDIUM 4.9

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences