lib/rpc/clnt_tcp.c · clnttcp_call()
Affects krb5Source GCVE Database
Not known to be exploited · CVSS 7.5 High.
Data as of 12 Nov 2026, 22:17 UTC
Thin evidence
One scorer or none| CNA (redhat) | CVSS 3.1 | 7.5 |
|---|
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 9 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10krb5pkg:deb/ubuntu/krb5?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSkrb5pkg:deb/ubuntu/krb5?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSkrb5pkg:deb/ubuntu/krb5?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSkrb5pkg:deb/ubuntu/krb5?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 20.04 LTSkrb5pkg:deb/ubuntu/krb5?arch=source&distro=focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSkrb5pkg:deb/ubuntu/krb5?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, mitigating actions may include limiting exposure of vulnerable services to untrusted networks and monitoring for unusual RPC retry activity.
Description
A vulnerability in the clnttcp_call() function of lib/rpc/clnt_tcp.c in MIT Kerberos 5 (krb5) allows remote attackers to cause a denial of service via a memory leak. This occurs because the RPC reply verifier is not freed between retries, enabling exploitation by injecting RPC replies with mismatched XIDs or triggering authentication retries.