CVE-2026-114617: Authlib: ID token can disable its own nonce validation via the nonce_supported claim
Noroxi assessment
Priority: Monitor (action score 16/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.26% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. Special conditions such as timing or configuration are required.
- Fixed version: authlib authlib 1.9.0.
Low priority for now. Upgrade to authlib authlib 1.9.0 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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 implicit and hybrid relying parties, or applications that directly accept externally supplied ID tokens, an attacker with a captured validly signed token can bypass the nonce-to-session binding and replay the victim's token into an attacker-controlled session. Plain authorization code flow is not affected, and the token must still pass signature, issuer, and audience validation. OpenIDMixin.parse_id_token() trusts nonce_supported in both authlib/integrations/base_client/sync_openid.py and authlib/integrations/base_client/async_openid.py to disable the expected nonce. This issue is fixed in version 1.9.0.
- Published
- Oct 22, 2026
- Updated
- Oct 29, 2026
- EPSS
- 0.2% · 18th percentile
- CWE
- CWE-294
Report tools
Action score
16
Low priority for now.
- CVSS
- 16 / 40 · 4.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 4.2
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| authlib | authlib | cpe:2.3:a:authlib:authlib |
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
authlib authlib
- < 1.9.0affected
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- authlib authlibbefore 1.9.0
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | python-authlib | from 0 | — |
| Debian:14 | python-authlib | before 1.9.1-1 | 1.9.1-1 |
| openSUSE:Tumbleweed | python-Authlib | before 1.9.1-1.1 | 1.9.1-1.1 |
| PyPI | authlib | before 1.9.0 | 1.9.0 |
Same product
authlib: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-104056Authlib version 1.7.2 and below contains a vulnerability where discovery JSON metadata is cached without validation or issuer-origin…39Monitor
- CVE-2026-96760Authlib library contains a signature‑verification bypass vulnerability39Monitor
- CVE-2026-114616Authlib accepts an empty HMAC key, allowing JWS/JWT signature forgery (HS256/HS384/HS512)36Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-114614Oct 22, 2026 · Authlib: is_secure_transport() loopback exemption can be bypassed with a userinfo component, allowing cleartext-HTTP URLs to non-loopback hosts14Monitor
- ← EarlierCVE-2026-114615Oct 22, 2026 · Authlib incomplete algorithm-confusion fix permits HMAC forgery with prefixed public keys36Monitor
- Later →CVE-2026-114618Oct 22, 2026 · Authlib: Default JWT bearer grant accepts assertions for the wrong audience27Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| authlib authlib | 1.9.0 · description | Vendor (CNA) |
| debian:python-authlib | 1.9.1-1 · Debian:14 | Package registry (OSV) |
| opensuse:python-Authlib | 1.9.1-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| PyPI:authlib | 1.9.0 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayNov 14, 2026+22 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Not on record for this CVE: researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-294 · Authentication Bypass by Capture-replayCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Session SidejackingCAPEC-102likelihood: High · High
- KerberoastingCAPEC-509High
- Remote Services with Stolen CredentialsCAPEC-555Very High
- Windows Admin Shares with Stolen CredentialsCAPEC-561
- Reusing Session IDs (aka Session Replay)CAPEC-60likelihood: High · High
- Use of Captured Hashes (Pass The Hash)CAPEC-644likelihood: Medium · High
- Use of Captured Tickets (Pass The Ticket)CAPEC-645likelihood: Low · High
- Use of Known Kerberos CredentialsCAPEC-652likelihood: Medium · High
ATT&CK techniques
- Remote ServicesT1021
- Remote Services:SMB/Windows Admin SharesT1021.002
- Email Collection:Remote Email CollectionT1114.002
- External Remote ServicesT1133
- Access Token Manipulation:Token Impersonation/TheftT1134.001
- Use Alternate Authentication Material:Pass The HashT1550.002
- Use Alternate Authentication Material:Pass The TicketT1550.003
- Use Alternate Authentication Material:Web Session CookieT1550.004
- Adversary-in-the-MiddleT1557
- Steal or Forge Kerberos TicketsT1558
- Steal or Forge Kerberos Tickets:KerberoastingT1558.003
Change log
- SSVC exploitation— → none
- Exploit maturity— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.