CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-112320 Krb5: mit krb5 kadmind unauthenticated memory leak dos via gss-rpc auth flavor switching
High (7.5) in red hat. EPSS 1.0% estimated probability of exploitation activity in the next 30 days.
On this page
The GSS-RPC transport layer in MIT Kerberos 5 (aka krb5) 1.4 and later does not release the previous authentication context when a client switches from an RPCSEC_GSS or AUTH_GSSAPI flavor to a non-GSS flavor on the same TCP connection. This allows remote attackers to cause a denial of service (memory exhaustion in kadmind) by repeatedly establishing and abandoning GSS authentication contexts.
Severity
- EPSS
- 1.0% estimated probability of exploitation activity in the next 30 days; 63rd percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: yes · Technical impact: partial, assessed 2026-11-12. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-772 Missing Release of Resource after Effective Lifetime
- Published
- Modified
- Assigned by
- redhat (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
- red hat:red hat enterprise linux 10
- red hat:red hat enterprise linux 10.2 extended update support
- red hat:red hat enterprise linux 6
- red hat:red hat enterprise linux 7
- red hat:red hat enterprise linux 8
- red hat:red hat enterprise linux 9
- red hat:red hat enterprise linux 9.8 extended update support
- red hat:red hat hardened images
Versions
From the CNA's record in the CVE List.
Fixed in
| Product | Fixed in |
|---|---|
| Red Hat Enterprise Linux 10 | 0:1.21.3-11.el10_3.2 |
| Red Hat Enterprise Linux 10.2 Extended Update Support | 0:1.21.3-10.el10_2.2 |
| Red Hat Enterprise Linux 9 | 0:1.21.1-10.el9_9.2 |
| Red Hat Enterprise Linux 9.8 Extended Update Support | 0:1.21.1-10.el9_8.3 |
| Red Hat Hardened Images | 1.22.3-0.1.hum1 |
Fix and patched versions
- Red Hat Red Hat Enterprise Linux 10: fixed in 0:1.21.3-11.el10_3.2
- Red Hat Red Hat Enterprise Linux 10.2 Extended Update Support: fixed in 0:1.21.3-10.el10_2.2
- Red Hat Red Hat Enterprise Linux 9: fixed in 0:1.21.1-10.el9_9.2
- Red Hat Red Hat Enterprise Linux 9.8 Extended Update Support: fixed in 0:1.21.1-10.el9_8.3
- Red Hat Red Hat Hardened Images: fixed in 1.22.3-0.1.hum1
- Red Hat, Rocky Linux, Alpine, Alpaquita: fixed package versions per release
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12, 13, 14 | krb5 | no fix listed | DEBIAN-CVE-2026-112320 |
| Ubuntu | 20.04:LTS, 22.04:LTS, 24.04:LTS and 5 more | krb5 | no fix listed | UBUNTU-CVE-2026-112320 |
| Red Hat | enterprise_linux:9::appstream | krb5-devel, krb5-debuginfo, krb5-debugsource and 7 more | 0:1.21.1-10.el9_9.2 | RHSA-2026:99715 |
| Red Hat | enterprise_linux:9::baseos | krb5, libkadm5, krb5-libs and 14 more | 0:1.21.1-10.el9_9.2 | RHSA-2026:99715 |
| Red Hat | enterprise_linux:10.3 | krb5, libkadm5, krb5-libs and 15 more | 0:1.21.3-11.el10_3.2 | RHSA-2026:99624 |
| Red Hat | enterprise_linux_eus:10.2 | krb5, libkadm5, krb5-libs and 15 more | 0:1.21.3-10.el10_2.2 | RHSA-2026:99625 |
| Red Hat | hummingbird:1 | krb5, libkadm5, krb5-libs and 7 more | 0:1.22.3-0.1.hum1 | RHSA-2026:97811 |
| Red Hat | rhel_eus:9.8::appstream | krb5-devel, krb5-debuginfo, krb5-debugsource and 7 more | 0:1.21.1-10.el9_8.3 | RHSA-2026:99716 |
| Red Hat | rhel_eus:9.8::baseos | krb5, libkadm5, krb5-libs and 14 more | 0:1.21.1-10.el9_8.3 | RHSA-2026:99716 |
| Rocky Linux | 9 | libkadm5, krb5-libs, krb5-devel and 14 more | 0:1.21.1-10.el9_9.2 | RLSA-2026:99715 |
| Rocky Linux | 10 | libkadm5, krb5-libs, krb5-devel and 14 more | 0:1.21.3-11.el10_3.2 | RLSA-2026:99624 |
| Alpine | v3.23, v3.24 | krb5 | 1.22.3-r0 | ALPINE-CVE-2026-112320 |
| Azure Linux | 3 | krb5 | no fix listed | AZL-113543 |
| Alpaquita | 23 | krb5 | 1.20.2-r5 | BELL-CVE-2026-112320 |
| Alpaquita | 25, stream | krb5 | 1.22.3-r0 | BELL-CVE-2026-112320 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0; Red Hat Security Data © Red Hat, Inc., CC BY 4.0; Rocky Linux's errata, BSD-3-Clause; the Alpine secdb, CC BY-SA 4.0; Microsoft's Azure Linux vulnerability data, MIT; BellSoft's OSV database, MIT. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu · Red Hat · Alpine · Alpaquita.
Red Hat
Red Hat rates this Important.
This vulnerability is rated with an Important severity because it enables unauthenticated remote attackers to trigger unbounded heap memory exhaustion, leading to a service crash or denial of service across exposed RPC services. In Red Hat Enterprise Linux environments, exploitation requires direct network reachability to daemons utilizing the internal GSS-RPC transport over persistent TCP connections, such as the Kerberos administration server (kadmind). Because the flaw does not facilitate remote code execution or unauthorized access to sensitive Kerberos database records, it does not warrant a Critical rating.
Restrict network access to kadmind to trusted hosts, or disable it in favor of kadmin.local server-side command line tool for administration operations if possible.
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | krb5-0:1.21.3-11.el10_3.2 | Fixed 2026-11-12 | RHSA-2026:99624 |
| Red Hat Enterprise Linux 10.2 Extended Update Support | krb5-0:1.21.3-10.el10_2.2 | Fixed 2026-11-12 | RHSA-2026:99625 |
| Red Hat Enterprise Linux 9 | krb5-0:1.21.1-10.el9_9.2 | Fixed 2026-11-12 | RHSA-2026:99715 |
| Red Hat Enterprise Linux 9.8 Extended Update Support | krb5-0:1.21.1-10.el9_8.3 | Fixed 2026-11-12 | RHSA-2026:99716 |
| Red Hat Enterprise Linux 6 | krb5 | Out of support scope | |
| Red Hat Enterprise Linux 7 | krb5 | Affected | |
| Red Hat Enterprise Linux 8 | krb5 | Affected | |
| Red Hat Hardened Images | krb5 | Affected |
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-112320.
Attack patterns (CAPEC)
- CAPEC-469 HTTP DoS Severity: Low
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.
References
- https://access.redhat.com/errata/RHSA-2026:97811
- https://access.redhat.com/errata/RHSA-2026:99624
- https://access.redhat.com/errata/RHSA-2026:99625
- https://access.redhat.com/errata/RHSA-2026:99715
- https://access.redhat.com/errata/RHSA-2026:99716
- https://access.redhat.com/security/cve/CVE-2026-112320
- https://bugzilla.redhat.com/show_bug.cgi?id=2478449