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Vulnerabilities

Vulnerability · CVE-2026-114615

Incomplete List of Disallowed Inputs

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-2026-114615. EPSS is 0.21%. 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
Critical9.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.21%
Remediation
Version ranges on file
Affected products
PyPI authlib · package pip · pip authlib · pypi authlib

## Summary carries the only guard that stops an asymmetric public key from being used as an HMAC secret in . That guard is — anchored at byte 0 — while the loader that consumes the identical bytes on the asymmetric path ( / ) skips anything before the line. A PEM public key or X.509 certificate carrying **one leading byte** — a newline, a space, four spaces of indentation, a UTF-8 BOM, or a comment line — is therefore not recognised, falls through, and becomes the HMAC secret. An attacker holding only the issuer's public key then mints an token with arbitrary claims that accepts as authentic. This is an incomplete fix of **CVE-2024-37568 / GHSA-5357-c2jx-v7qh**. That advisory's fix is exactly this guard ( returns a single commit, "fix: prevent OctKey to import ssh/rsa/pem keys", referencing issue #654), and the original attack works again unchanged whenever the stored PEM does not start at offset 0. Reproduced end-to-end on **1.8.0**, the newest release (published 2026-08-30), and on ( ), with 50.0.2. ## Preconditions Both are deployment properties; neither is attacker-controlled at request time, and the attacker needs no secret and no user interaction. 1. **The relying party uses the documented module-level object.** is built at with the full list , and ( ) exposes **no parameter**, so a caller of the documented object has no way to narrow it. This is the first code sample in . This hazard is already documented: says "This decoding method is insecure. By default parses the alg header. This allows symmetric macs and asymmetric signatures.", and says "You should never combine symmetric (HS) and asymmetric (RS, ES, PS) signature schemes." The point of this report is **not** that the mixed list exists — it is that the backstop shipped for precisely that documented hazard does not hold. 2. **The verification key is passed as PEM/certificate text whose bytes do not begin at offset 0 with .** Each of the following forms was confirmed to forge, and each also still verifies

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 authlib1.3.1 → 1.9.0
  • package pipversion unspecified
  • pip authlib>= 1.3.1, <= 1.8.0
  • pypi authlibversion unspecified

How to fix CVE-2026-114615

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-2026-114615. EPSS is 0.21%. 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 1.3.1 → 1.9.0, >= 1.3.1, <= 1.8.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-184; CWE-347: Improper Verification of Cryptographic Signature. EPSS 0.21%. 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 improper asymmetric key validation

  2. Oct 27, 2026 · GitHub Advisory Database

    Updated

    ## Summary carries the only guard that stops an asymmetric public key from being used as an HMAC secret in . That guard is — anchored at byte 0 — while the loader that consumes the identical bytes on the asymmetric path ( / ) skips anything before the line. A PEM public key or X.509 certificate carrying **one leading byte** — a newline, a space, four spaces of indentation, a UTF-8 BOM, or a commen

  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 carries the only guard that stops an asymmetric public key from being used as an HMAC secret in . That guard is — anchored at byte 0 — while the loader that consumes the identical bytes on the asymmetric path ( / ) skips anything before the line. A PEM public key or X.509 certificate carrying **one leading byte** — a newline, a space, four spaces of indentation, a UTF-8 BOM, or a commen

Sources

  • CVE.orgVulnerability recordCVE-2026-114615

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-114615

    30-day exploitation probability 0.21%

    first.org
  • GitHub Advisory DatabasePackage advisoryGHSA-7vr2-2fgp-9w7p

    Authlib incomplete algorithm-confusion fix permits HMAC forgery with prefixed public keys

    github.com
  • GitLab Advisory DatabasePackage advisoryCVE-2026-114615

    OctKey.import_key() carries the only guard that stops an asymmetric public key from being used as an HMAC secret in authlib.jose. That guard is raw_key.startswith(POSSIBLE_UNSAFE_KEYS) — anchored at byte 0 — while the loader that consumes the identical bytes on the asymmetric path (cryptography.hazmat.primitives.serialization.load_pem_public_key / load_pem_x509_certificate) skips anything before t

    advisories.gitlab.com
  • PyPA Advisory DatabasePackage advisoryGHSA-7vr2-2fgp-9w7p

    Authlib incomplete algorithm-confusion fix permits HMAC forgery with prefixed public keys

    osv.dev
  • PyPA Advisory DatabasePackage advisoryPYSEC-2026-4355

    Authlib is a Python library which builds OAuth and OpenID Connect servers. From 1.3.1 until 1.9.0, OctKey.import_key() checks asymmetric-key markers only at byte zero while Authlib's PEM loaders accept leading whitespace, comments, or a byte-order mark. In deployments that use th

    osv.dev
  • Red Hat Security DataVendor advisoryCVE-2026-114615

    authlib: Authlib: Authentication bypass via improper asymmetric key validation

    access.redhat.com
  • Snyk Vulnerability DatabasePackage advisorySNYK-PYTHON-AUTHLIB-21460693

    Incomplete List of Disallowed Inputs

    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