CyberSecBulletin
CVE-2026-46419NVD status: Deferred

webauthn-server-core: Incorrect Check of Function Return Value

Published Updated By the CyberSecBulletin desk

CVE-2026-46419 is a high-severity incorrect check of function return value vulnerability in webauthn-server-core from Yubico, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 2.8.2 as the first without the flaw, so updating webauthn-server-core to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.31% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update webauthn-server-core to 2.8.2 or a later version.
  2. Read the advisory on yubico.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Yubicowebauthn-server-core2.8.0 up to, but not including, 2.8.22.8.2

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (mitre.org).

Official description

Yubico webauthn-server-core (aka java-webauthn-server) 2.8.0 before 2.8.2 incorrectly checks a function's return value in the second factor flow, leading to impersonation.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Incorrect Check of Function Return Value

The product incorrectly checks a return value from a function, which prevents it from detecting errors or exceptional conditions.

How developers prevent this class of flaw

  • Use a language or compiler that uses exceptions and requires the catching of those exceptions.
  • Properly check all functions which return a value.
  • When designing any function make sure you return a value or throw an exception in case of an error.

More Incorrect Check of Function Return Value vulnerabilities (CWE-253)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Incorrect Check of Function Return Value vulnerabilities

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