Krb5: mit krb5 kadmind unauthenticated cpu dos via auth_gssapi client states cleanup
- Exploited
- No known exploitation
- Fix
- No fix listed
- Who is exposed
- Not reported
Do first: Workaround: Restrict network access to kadmind to trusted hosts, or disable kadmind in favor of the kadmin.local tool if possible.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 43/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
MIT Kerberos 5 (krb5) is affected through its kadmind administration service, where a remote attacker can exhaust CPU and cause a denial of service. The attacker can do this over the network without logging in, by accumulating a large number of AUTH_GSSAPI client entries.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
clean_client() in lib/rpc/svc_auth_gssapi.c in MIT Kerberos 5 (aka krb5) restarts its scan from the head of the client list after each removal, resulting in quadratic CPU cost. Remote attackers can cause a denial of service (CPU consumption in kadmind) by accumulating a large number of AUTH_GSSAPI client entries.
cve.now Index
- Exploitation0/40No signal
- Exposure20/25No login or user action needed, CISA rates it automatable · Unknown: Advisories don't say whether default setups are affected
- Reach10/20Shipped in major Linux distributions
- Severity7.5/10CVSS 7.5
- No patch5/5No patch listed yet
What would change the score
- Would score about 88 if added to CISA KEV
- Would score about 83 if CISA's SSVC rates exploitation active
- Would score about 48 if advisories confirm default setups are exposed
What to do
Workaround: Restrict network access to kadmind to trusted hosts, or disable kadmind in favor of the kadmin.local tool if possible.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- krb5
Version range not reported
- krb5
Version range not reported
- krb5
Version range not reported
- krb5
Version range not reported
- krb5
Version range not reported
- krb5
Version range not reported
Evidence 2
- Report
- Link
Corrections
None so far.
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Questions about CVE-2026-112322
Is CVE-2026-112322 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A remote client that does not log in can make the krb5 kadmind service use up CPU time while it cleans up its GSSAPI client state, which can cause a prolonged denial of service. The stated impact is availability only, with no confidentiality or integrity impact.Source: bugzilla.redhat.com, access.redhat.com
Am I affected, and how do I check?
The issue applies only where a network-reachable service from the krb5 package uses the legacy AUTH_GSSAPI server path, such as kadmind. Red Hat Enterprise Linux 6, 7, 8, 9 and 10, and Red Hat Hardened Images are listed as products, but no version ranges are given. To check, look at whether kadmind is running and reachable over the network and whether the legacy AUTH_GSSAPI path is enabled in its configuration.Source: bugzilla.redhat.com, access.redhat.com
How do I fix CVE-2026-112322?
No released package fix is established yet, so no upgrade target can be named from the checked facts. Follow the vendor advisory for when a patched krb5 package becomes available.Source: bugzilla.redhat.com, access.redhat.com
What if there's no patch?
Restrict network access to kadmind to trusted hosts, or disable kadmind and use the kadmin.local tool instead if that is possible. These steps limit who can reach the affected service until a fix is released.Source: bugzilla.redhat.com, access.redhat.com