CVE-2026-82462
pac4j-oidc before 6.5.6 Authentication Bypass via Access Token Substitution
Description
pac4j-oidc before 6.5.6 accepts OIDC callbacks carrying only an access token without authorization code or ID token validation. Attackers can substitute access tokens minted for other clients to create authenticated sessions without proper issuer, audience, nonce, or subject verification.
INFO
Published Date :
Aug. 29, 2026, 5:17 p.m.
Last Modified :
Aug. 29, 2026, 5:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update pac4j-oidc to version 6.5.6 or later.
- Ensure access tokens are validated.
- Verify issuer, audience, nonce, and subject.
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-2026-82462.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-82462 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-2026-82462
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).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-82462 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-82462 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.
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New CVE Received by [email protected]
Aug. 29, 2026
Action Type Old Value New Value Added Description pac4j-oidc before 6.5.6 accepts OIDC callbacks carrying only an access token without authorization code or ID token validation. Attackers can substitute access tokens minted for other clients to create authenticated sessions without proper issuer, audience, nonce, or subject verification. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/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 CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Added CWE CWE-345 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/82xxx/CVE-2026-82462.json">CVE-2026-82462</a> Added Reference https://github.com/pac4j/pac4j Added Reference https://github.com/pac4j/pac4j/blob/pac4j-parent-6.5.5/pac4j-oidc/src/main/java/org/pac4j/oidc/credentials/extractor/OidcCredentialsExtractor.java Added Reference https://github.com/pac4j/pac4j/commit/2270c3ff70e93cc43831e75702acd5135531237e Added Reference https://www.pac4j.org/blog/security-advisory-pac4j-core-oidc-saml.html Added Reference https://www.vulncheck.com/advisories/pac4j-oidc-before-6.5.6-authentication-bypass-via-access-token-substitution