---
id: "CVE-2026-112321"
page: "https://infrastack.ai/live/CVE-2026-112321"
kind: "vulnerability"
aliases: ["CVE-2026-112321"]
title: "MIT Kerberos 5: memory leak lets remote requests exhaust kadmind memory"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "krb5", "fixed": ["1.22.3"], "affected": "< 1.22.3 (lower bound unknown)", "ecosystem": "vendor"}]
ecosystems: []
tags: ["kadmind", "kerberos", "mit-kerberos", "package", "self-hosted"]
not_affected_if: ["kadmind-not-running", "network-restricted"]
published_at: "2026-11-09T19:16:41+00:00"
first_seen_at: "2026-11-09T19:28:13+00:00"
updated_at: "2026-11-09T19:37:13+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-112321", "first_seen_at": "2026-11-09T19:28:13+00:00"}, {"source": "analyst", "url": "https://web.mit.edu/kerberos/advisories/MITKRB5-SA-2026-001.txt", "first_seen_at": "2026-11-09T19:37:13+00:00", "cites": ["https://web.mit.edu/kerberos/advisories/MITKRB5-SA-2026-001.txt"]}]
exploit_sources: []
---

# MIT Kerberos 5: memory leak lets remote requests exhaust kadmind memory

Link for people: https://infrastack.ai/live/CVE-2026-112321 (this .md is for agents)

The AUTH_GSSAPI handler in MIT Kerberos 5 does not free decoded arguments on some error paths. A remote attacker can send crafted AUTH_GSSAPI_INIT requests that trigger authentication failures and exhaust memory in kadmind, causing denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:krb5 affected < 1.22.3 (lower bound unknown) fixed 1.22.3

## How to check

- Check the krb5 version (rpm -q krb5-server / dpkg -l krb5-admin-server); below 1.22.3 may be affected, though distro builds may backport fixes. The lower bound of affected versions is not stated by MIT.
- Check whether kadmind is running and whether its port (749/tcp) is reachable from untrusted networks.

## Fix

Upgrade MIT krb5 to 1.22.3 or later (MITKRB5-SA-2026-001 lists this CVE among its DoS fixes; no per-CVE mapping given). Distro packages: use the vendor's backport.

## Timeline

- 2026-11-09T19:28:13+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-112321
- 2026-11-09T19:37:13+00:00 analyst https://web.mit.edu/kerberos/advisories/MITKRB5-SA-2026-001.txt — MIT advisory MITKRB5-SA-2026-001 (read via page summarizer; Exa credits exhausted) lists this CVE in its DoS section and is a patch release 1.22.3; no per-CVE detail or affected lower bound. Fix inferred from advisory-level release, so nothing marked verified. Re-read raw advisory to confirm. Siblings CVE-2026-112323 and -119079 are in same advisory.

## Documents

- [advisory] MITKRB5-SA-2026-001: Multiple vulnerabilities fixed in 1.22.3 https://web.mit.edu/kerberos/advisories/MITKRB5-SA-2026-001.txt

## From the sources

The AUTH_GSSAPI handler in lib/rpc/svc_auth_gssapi.c in MIT Kerberos 5 (aka krb5) does not free decoded arguments on certain error paths, which allows remote attackers to cause a denial of service (memory exhaustion in kadmind) via crafted AUTH_GSSAPI_INIT requests that trigger authentication failures.

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