Apache Kerby: Kerberos Pre-Authentication Bypass
It is possible to bypass the Kerberos pre-authentication check in Apache Kerby by sending a PA-DATA with an unrecognized or unsupported type. Users are recommended to upgrade to version 2.1.2, which fixes this issue.
- Published
- Jun 26, 2026
- Updated
- Aug 3, 2026
- EPSS
- 0.5% · 43th percentile
- CWE
- CWE-304
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Report tools
Action score
29
Monitor
Low priority for now.
- CVSS
- 29 / 40 · 7.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| amq clients | 2023 | cpe:2.3:redhat:amq_clients:2023 |
| jboss data grid | 8 | cpe:2.3:redhat:jboss_data_grid:8 |
| jboss fuse | 7 | cpe:2.3:redhat:jboss_fuse:7 |
| jbosseapxp | cpe:2.3:redhat:jbosseapxp:undefined | |
| amq streams | 2 | cpe:2.3:redhat:amq_streams:2 |
| amq streams | 3 | cpe:2.3:redhat:amq_streams:3 |
Versions reported by the vendor
Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.
Apache Software Foundation Apache Kerby
- before 2.1.2affected · semver
Same product
apache software foundation: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-57914Apache Kerby: StackOverflow on parsing deeply nested ASN1 structures26Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Apache Software Foundation Apache Kerby | 2.1.2 | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0458 · Jun 29, 2026(Apache Çoklu Ürün Güvenlik Bildirimi)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- Low
Weakness class (CWE)
CWE-304 · Missing Critical Step in AuthenticationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.apache.org/thread/1y3glgh3kzwoxo5m2lq504cjlh1dsrfh
- www.openwall.com/lists/oss-security/2026/06/26/8
- access.redhat.com/security/cve/CVE-2026-57915
- bugzilla.redhat.com/show_bug.cgi?id=2493407
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-57915.json
Vendor advisories and official records. Exploit/PoC links are deliberately left out.