CVE-2026-11883Public exploitNetwork attack vector

2FA bypass via null WebAuthn response

Published Jul 1, 2026 · Updated Jul 1, 2026

Authentication bypass in WebAuthn Provider for Two Factor before 2.5.6 allows remote attackers with a valid password to skip WebAuthn. The second-factor handler accepts the JSON literal null in the webauthn_response field instead of rejecting the malformed value. Exploitation requires a target account's correct password and grants that account's WordPress access without its registered authenticator.

CVSS severity7.2
High
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in WebAuthn Provider for Two Factor before 2.5.6 allows remote attackers with a valid password to skip WebAuthn. The second-factor handler accepts the JSON literal null in the webauthn_response field instead of rejecting the malformed value. Exploitation requires a target account's correct password and grants that account's WordPress access without its registered authenticator.

The record

CVE
CVE-2026-11883
Published
Jul 1, 2026
Updated
Jul 1, 2026
Vendor
Volodymyr Kolesnykov
Product
WebAuthn Provider for Two Factor
Classifications
CWE-287, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.5.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Volodymyr Kolesnykov · WebAuthn Provider for Two Factorversion=0 <2.5.6

Published CVSS scores

7.2CISA-ADPCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
T1078Valid Accounts

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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