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Vulnerabilities

Vulnerability · CVE-2026-114617

Replay Attack

Published Oct 22, 2026 · catalog updated Oct 30, 2026 · Red Hat Red Hat Enterprise Linux

Last checked Nov 5, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-114617. EPSS is 0.27%. Act only if a listed version of Red Hat Red Hat Enterprise Linux is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium6.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.27%
Remediation
Version ranges on file
Affected products
PyPI authlib · package pip · pip authlib · pypi authlib

### Summary reads the claim from the ID token it is validating. When that claim is boolean , the expected nonce is set to and nonce validation is skipped for that token. An ID token that carries this claim is therefore accepted in a session whose nonce does not match. A captured, validly signed ID token belonging to a victim can be replayed into an attacker-controlled session, authenticating the attacker as the victim at the relying party. The code is identical in and , so all framework integrations are affected. Fixed versions: none; reproduced on 1.8.0 (commit c529a61a). Preconditions: the ID token must carry a valid signature and pass and validation, and the attacker must be able to supply it to . Authorization code flow is not affected. Implicit and hybrid relying parties, and applications calling directly, are affected. ### Details ## Affected code , in : contains the same code. ## Source of the claim is constructed from , which is the decoded payload of the ID token passed to : therefore resolves against the ID token payload. It is not read from , from client configuration, or from any other source under the relying party's control. ## Effect on validation at performs the comparison only when the expected value is truthy: Assigning makes falsy, so both the presence check and the equality check are skipped. No error is raised and completes normally. The docstring of that same method states the requirement: > If present in the ID Token, Clients MUST verify that the nonce Claim Value is equal to the value of the nonce parameter sent in the Authentication Request. ## Trigger condition The comparison is , so only a JSON boolean activates the branch. A string value does not, and nonce validation proceeds normally in that case. ## Origin The branch was added in commit ("Skip verifying nonce for Apple case") to accommodate a provider that emits a claim, as referenced by the inline comment pointing to issue #259. ## Remediation Read the flag from server metadata or cli

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • PyPI authlib0 → 1.9.0
  • package pipversion unspecified
  • pip authlib<= 1.8.0
  • pypi authlibversion unspecified

How to fix CVE-2026-114617

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-114617. EPSS is 0.27%. Act only if a listed version of Red Hat Red Hat Enterprise Linux is installed.

Which versions are affected?

Compare what you have installed with 0 → 1.9.0, <= 1.8.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-294; CWE-807. EPSS 0.27%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 22, 2026 · Red Hat Security Data

    Detected

    authlib: Authlib: Authentication bypass via disabled nonce verification in OpenID Connect tokens

  2. Oct 27, 2026 · GitHub Advisory Database

    Updated

    ### Summary reads the claim from the ID token it is validating. When that claim is boolean , the expected nonce is set to and nonce validation is skipped for that token. An ID token that carries this claim is therefore accepted in a session whose nonce does not match. A captured, validly signed ID token belonging to a victim can be replayed into an attacker-controlled session, authenticating the a

  3. Oct 30, 2026 · PyPA Advisory Database

    Fix available

    authlib fixed in 1.9.0

  4. Oct 30, 2026 · PyPA Advisory Database

    Fix available

    authlib fixed in 1.9.0

  5. Oct 30, 2026 · PyPA Advisory Database

    Updated

    ### Summary reads the claim from the ID token it is validating. When that claim is boolean , the expected nonce is set to and nonce validation is skipped for that token. An ID token that carries this claim is therefore accepted in a session whose nonce does not match. A captured, validly signed ID token belonging to a victim can be replayed into an attacker-controlled session, authenticating the a

Sources

  • CVE.orgVulnerability recordCVE-2026-114617

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-114617

    30-day exploitation probability 0.27%

    first.org
  • GitHub Advisory DatabasePackage advisoryGHSA-c5mf-xmp2-59rc

    Authlib: ID token can disable its own nonce validation via the nonce_supported claim

    github.com
  • GitLab Advisory DatabasePackage advisoryCVE-2026-114617

    OpenIDMixin.parse_id_token() reads the nonce_supported claim from the ID token it is validating. When that claim is boolean false, the expected nonce is set to None and nonce validation is skipped for that token. An ID token that carries this claim is therefore accepted in a session whose nonce does not match. A captured, validly signed ID token belonging to a victim can be replayed into an attack

    advisories.gitlab.com
  • PyPA Advisory DatabasePackage advisoryGHSA-c5mf-xmp2-59rc

    Authlib: ID token can disable its own nonce validation via the nonce_supported claim

    osv.dev
  • PyPA Advisory DatabasePackage advisoryPYSEC-2026-4357

    Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, OpenIDMixin.parse_id_token() reads the nonce_supported decision from the untrusted ID token being validated and sets the expected nonce to null when that claim is the JSON boolean false. In

    osv.dev
  • Red Hat Security DataVendor advisoryCVE-2026-114617

    authlib: Authlib: Authentication bypass via disabled nonce verification in OpenID Connect tokens

    access.redhat.com
  • Snyk Vulnerability DatabasePackage advisorySNYK-PYTHON-AUTHLIB-21460690

    Replay Attack

    security.snyk.io

References

Freshness

Last verified in this catalog Nov 5, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 5, 2026
  • PyPA Advisory DatabaseOct 30, 2026
  • PyPA Advisory DatabaseOct 30, 2026
  • GitLab Advisory DatabaseOct 28, 2026
  • GitHub Advisory DatabaseOct 28, 2026
  • Snyk Vulnerability DatabaseOct 25, 2026
  • Red Hat Security DataOct 24, 2026
  • CVE.orgOct 23, 2026