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Vulnerabilities

Vulnerability · CVE-2026-114618

Improper Validation of Integrity Check Value

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-2026-114618. EPSS is 0.35%. 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
0.35%
Remediation
Version ranges on file
Affected products
PyPI authlib · package pip · pip authlib · pypi authlib

## Description ### Summary Authlib's default RFC 7523 JWT bearer grant leaves empty, so only checks that an claim *exists* instead of requiring it to match the current authorization server's token endpoint. An attacker holding a legitimately issued JWT assertion for *any* audience can present it to a different authorization server sharing the same signing key and obtain an access token. To be completely transparent, AI tools helped surface it. However, we have independently reproduced and carefully validated the issue. We follow responsible disclosure practices and are sharing this privately. ### Affected Entrypoints - — default returns empty list - with for audience validation - when audience checking is enabled ### Exploit Path ### Proof of Concept ### Observed Result - **Default grant (vulnerable):** HTTP 200, issued despite - **Strict grant (fixed):** HTTP 400, — correctly rejects mismatched audience - Confirms the default returns empty, so audience validation is effectively skipped ### Impact - **Vulnerability Type:** CWE-287 — Improper Authentication - An attacker with a valid JWT assertion for *any* service can use it to obtain tokens from a *different* service sharing the same signing keys - Particularly dangerous in **microservice architectures** where services share identity infrastructure - Enables unauthorized access escalation across trust boundaries - The vulnerability is in the *default behavior* — most integrations won't override --- ### Credit Reported by a security research team from the University of Sydney, focusing on detecting open source software vulnerabilities. Liyi Zhou: https://lzhou1110.github.io/ Ziyue Wang: https://zyy0530.github.io/ Strick: https://str1ckl4nd.github.io/ Maurice: https://maurice.busystar.org/ Chenchen Yu: https://7thparkk.github.io/

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< 1.9.0
  • pypi authlibversion unspecified

How to fix CVE-2026-114618

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-2026-114618. EPSS is 0.35%. 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, < 1.9.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-1188; CWE-287: Improper Authentication; CWE-358. EPSS 0.35%. 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: Unauthorized access via improper JWT audience validation

  2. Oct 27, 2026 · GitHub Advisory Database

    Updated

    ## Description ### Summary Authlib's default RFC 7523 JWT bearer grant leaves empty, so only checks that an claim *exists* instead of requiring it to match the current authorization server's token endpoint. An attacker holding a legitimately issued JWT assertion for *any* audience can present it to a different authorization server sharing the same signing key and obtain an access token. To be comp

  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

    ## Description ### Summary Authlib's default RFC 7523 JWT bearer grant leaves empty, so only checks that an claim *exists* instead of requiring it to match the current authorization server's token endpoint. An attacker holding a legitimately issued JWT assertion for *any* audience can present it to a different authorization server sharing the same signing key and obtain an access token. To be comp

Sources

  • CVE.orgVulnerability recordCVE-2026-114618

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-114618

    30-day exploitation probability 0.35%

    first.org
  • GitHub Advisory DatabasePackage advisoryGHSA-fch4-3c6x-j4gc

    Authlib: Default JWT bearer grant accepts assertions for the wrong audience

    github.com
  • GitLab Advisory DatabasePackage advisoryCVE-2026-114618

    Authlib's default RFC 7523 JWT bearer grant leaves get_audiences() empty, so verify_claims() only checks that an aud claim exists instead of requiring it to match the current authorization server's token endpoint. An attacker holding a legitimately issued JWT assertion for any audience can present it to a different authorization server sharing the same signing key and obtain an access token. To be

    advisories.gitlab.com
  • PyPA Advisory DatabasePackage advisoryGHSA-fch4-3c6x-j4gc

    Authlib: Default JWT bearer grant accepts assertions for the wrong audience

    osv.dev
  • Red Hat Security DataVendor advisoryCVE-2026-114618

    authlib: Authlib: Unauthorized access via improper JWT audience validation

    access.redhat.com
  • Snyk Vulnerability DatabasePackage advisorySNYK-PYTHON-AUTHLIB-21460692

    Improper Validation of Integrity Check Value

    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
  • 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