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WebAuthn4J Spring Security Improper signature counter value handlingGHSA-v9hx-v6vf-g36j

MEDIUMFix: webauthn4j/webauthn4j-spring-security@129700d

GHSA-v9hx-v6vf-g36j is a medium-severity (CVSS 4.8) Improper Authentication vulnerability in com.webauthn4j:webauthn4j-spring-security-core. A fix is available for com.webauthn4j:webauthn4j-spring-security-core — see the affected versions and patch details below.

Also known asCVE-2023-45669
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-v9hx-v6vf-g36j.

EPSS Exploitation Probability

via FIRST.org ↗
0.6%probability of exploitation in next 30 days
Lower Risk+0.12%
Lower risk than most CVEs51th percentile — riskier than 51% of all scored CVEsHighest risk
0.00%0.38%0.76%1.14%0.4%0.6%May 26Aug 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
☕com.webauthn4j:webauthn4j-spring-security-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Improper signature counter value handling

Impact

A flaw was found in webauthn4j-spring-security-core. When an authneticator returns an incremented signature counter value during authentication, webauthn4j-spring-security-core does not properly persist the value, which means cloned authenticator detection does not work. An attacker who cloned valid authenticator in some way can use the cloned authenticator without being detected.

Patches

Please upgrade to com.webauthn4j:webauthn4j-spring-security-core:0.9.1.RELEASE

References

For more details about WebAuthn signature counters, see WebAuthn specification 6.1.1. Signature Counter Considerations.

Reporter

This issue was discovered by Michael Budnick (@mbudnick)

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
☕Mavencom.webauthn4j:webauthn4j-spring-security-coreall versions0.9.1.RELEASEcom.webauthn4j:webauthn4j-spring-security-core:0.9.1.RELEASE

Affected Products

1 product · 1 configurations
Application
spring securitywebauthn4j
< 0.9.1
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.webauthn4j:webauthn4j-spring-security-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update com.webauthn4j:webauthn4j-spring-security-core to 0.9.1.RELEASE or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-v9hx-v6vf-g36j is resolved across your whole dependency graph.

  3. Workarounds

    Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

Improper signature counter value handling ### Impact A flaw was found in webauthn4j-spring-security-core. When an authneticator returns an incremented signature counter value during authentication, webauthn4j-spring-security-core does not properly persist the value, which means cloned authenticator detection does not work. An attacker who cloned valid authenticator in some way can use the cloned authenticator without being detected. ### Patches Please upgrade to `com.webauthn4j:webauthn4j-spring-security-core:0.9.1.RELEASE` ### References For more details about WebAuthn signature counte
O3 Security · Impact-Aware SCA

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WebAuthn4J Spring Security Improper signature counter…