CVE-2026-57915Network attack vector

Unauthenticated pre-authentication bypass via unchecked PA-DATA type

Published Jun 26, 2026 · Updated Jun 26, 2026

Authentication bypass in Apache Kerby before 2.1.2 allows remote attackers to skip required Kerberos pre-authentication via crafted PA-DATA. The KDC validator treats any PA-DATA entry as satisfying the requirement instead of requiring at least one recognized, valid mechanism. A network-reachable KDC with pre-authentication required accepts an unsupported type, weakening the authentication gate for affected principals.

CVSS severity7.3
High
EPSS probability0.53%
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 Apache Kerby before 2.1.2 allows remote attackers to skip required Kerberos pre-authentication via crafted PA-DATA. The KDC validator treats any PA-DATA entry as satisfying the requirement instead of requiring at least one recognized, valid mechanism. A network-reachable KDC with pre-authentication required accepts an unsupported type, weakening the authentication gate for affected principals.

The record

CVE
CVE-2026-57915
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
The Apache Software Foundation
Product
Apache Kerby
Classifications
CWE-304, CWE-358, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 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 <2.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Kerbyversion=0 <2.1.2

Published CVSS scores

7.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
7.3Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-304Missing Critical Step in Authentication
CWE-358Improperly Implemented Security Check for Standard
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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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