VulnerabilityPublished 10 Mar 2026

CVE-2026-30964: web-auth webauthn-lib · Origin Validation Error

Affects web-auth webauthn-libSource CVE Database V5

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Not known to be exploited · CVSS 5.4 Medium : upgrade to 5.2.4 when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

5.4Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.2.4

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade webauthn-framework and webauthn-lib and webauthn-symfony-bundle and web-auth/webauthn-framework to 5.2.4.

Affected software

Product	Affected	Fixed in
web-authwebauthn-framework	Affected <5.2.4	Fixed in 5.2.4
web-authwebauthn-lib	Affected <5.2.4	Fixed in 5.2.4
web-authwebauthn-symfony-bundle	Affected <5.2.4	Fixed in 5.2.4
Packagistweb-auth/webauthn-framework`pkg:composer/web-auth/webauthn-framework`Other threats	Affected <5.2.4	Fixed in 5.2.4

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations should upgrade the web-auth webauthn-framework to version 5.2.4 or later, where the origin validation logic correctly enforces exact origin matching including scheme and port. Until upgrade is possible, developers should implement additional server-side origin checks that verify the full origin string rather than just the host component. Security teams should audit their WebAuthn implementations to confirm they do not rely solely on host-based origin validation. Web application firewalls (WAFs) can be configured to detect and block suspicious cross-origin requests that do not match expected schemes and ports. Monitoring authentication logs for unusual origin patterns or failed authentication attempts from unexpected origins can help detect exploitation attempts. Educating developers about the importance of strict origin validation in WebAuthn flows is also recommended to prevent similar issues.

Description

web-auth/webauthn-lib is an open source set of PHP libraries and a Symfony bundle to allow developers to integrate that authentication mechanism into their web applications. Prior to 5.2.4, when allowed_origins is configured, CheckAllowedOrigins reduces URL-like values to their host component and accepts on host match alone. This makes exact origin policies impossible to express: scheme and port differences are silently ignored. This vulnerability is fixed in 5.2.4.

Impact

The vulnerability undermines the origin validation mechanism critical to WebAuthn authentication flows, potentially allowing attackers to bypass origin restrictions. This can lead to unauthorized authentication attempts, session hijacking, or cross-origin attacks that compromise user credentials or session integrity. Organizations using vulnerable versions of the webauthn-framework may face increased risk of account takeover or impersonation attacks. The impact is primarily on confidentiality and integrity of authentication processes, with no direct availability impact. Because WebAuthn is increasingly adopted for strong passwordless authentication, exploitation could erode trust in authentication security and expose sensitive user accounts. The vulnerability affects any web application integrating the vulnerable library versions, especially those exposed to untrusted networks or users. While no known exploits are reported, the ease of exploitation due to lack of required privileges and remote accessibility makes timely remediation important to prevent potential attacks.

Summary

The web-auth webauthn-framework is a PHP library and Symfony bundle that facilitates integration of WebAuthn authentication into web applications. Prior to version 5.2.4, when the allowed_origins configuration was set, the framework's CheckAllowedOrigins function performed origin validation by reducing URL-like values to their host component only. This means that the scheme (e.g., http vs https) and port number were ignored during origin checks. As a result, the origin validation was incomplete and allowed origin policies could not be precisely enforced. An attacker could exploit this by crafting requests from origins that share the same host but differ in scheme or port, bypassing origin restrictions. This vulnerability is classified under CWE-346 (Origin Validation Error). The CVSS 3.1 base score is 5.4 (medium severity), reflecting that the vulnerability is remotely exploitable without privileges but requires user interaction and results in limited confidentiality and integrity impact without affecting availability. The flaw could lead to unauthorized authentication or cross-origin request forgery scenarios, undermining the security guarantees of WebAuthn implementations relying on this library. The issue was addressed in version 5.2.4 by enforcing exact origin matching that includes scheme and port, restoring strict origin policy enforcement.

CWE-346Origin Validation Error (opens in a new tab)
Class weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product does not properly verify that the source of data or communication is valid.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V14.5.2 (opens in a new tab)
V14.5.3 (opens in a new tab)
V1.4.4 (opens in a new tab)
Attack patterns
JSON Hijacking (aka JavaScript Hijacking) (opens in a new tab)
Cache Poisoning (opens in a new tab)
DNS Cache Poisoning (opens in a new tab)
Exploit Script-Based APIs (opens in a new tab)
Application API Message Manipulation via Man-in-the-Middle (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Mar 2026, 18:09 UTC

WeaknessesCWE-346

Technical details

References

Community reviews

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