Red Hat Security Advisory: krb5 security update
Kerberos is a network authentication system, which can improve the security of your network by eliminating the insecure practice of sending passwords over the network in unencrypted form. It allows clients and servers to authenticate to each other with the help of a trusted third party, the Kerberos key distribution center (KDC). Security Fix(es): * krb5: MIT Kerberos 5 (krb5): Denial of Service via integer underflow and out-of-bounds read (CVE-2026-40356) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
AI Analysis
Technical Summary
The vulnerability CVE-2026-40356 in MIT Kerberos 5 (krb5) involves a denial of service caused by an integer underflow and out-of-bounds read. This affects Red Hat Enterprise Linux 9.4 and related variants. The vulnerability could allow an attacker to disrupt the Kerberos authentication service. Red Hat Product Security has issued an advisory (RHSA-2026:24686) and released updated krb5 packages to fix this issue. The advisory rates the security impact as Important and provides updated packages for multiple architectures including x86_64, aarch64, ppc64le, and s390x. No CVSS score is provided in the advisory.
Potential Impact
The vulnerability allows denial of service (DoS) against the Kerberos authentication service by exploiting an integer underflow and out-of-bounds read. This could disrupt authentication processes relying on Kerberos, potentially impacting network security and availability of services that depend on it. There are no known exploits in the wild at this time.
Mitigation Recommendations
Red Hat has released updated krb5 packages for Red Hat Enterprise Linux 9.4 and related variants to address this vulnerability. Users should apply the official security update as described in Red Hat advisory RHSA-2026:24686 and the referenced update article (https://access.redhat.com/articles/11258). Applying these updates will remediate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Red Hat Security Advisory: krb5 security update
Description
Kerberos is a network authentication system, which can improve the security of your network by eliminating the insecure practice of sending passwords over the network in unencrypted form. It allows clients and servers to authenticate to each other with the help of a trusted third party, the Kerberos key distribution center (KDC). Security Fix(es): * krb5: MIT Kerberos 5 (krb5): Denial of Service via integer underflow and out-of-bounds read (CVE-2026-40356) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-40356 in MIT Kerberos 5 (krb5) involves a denial of service caused by an integer underflow and out-of-bounds read. This affects Red Hat Enterprise Linux 9.4 and related variants. The vulnerability could allow an attacker to disrupt the Kerberos authentication service. Red Hat Product Security has issued an advisory (RHSA-2026:24686) and released updated krb5 packages to fix this issue. The advisory rates the security impact as Important and provides updated packages for multiple architectures including x86_64, aarch64, ppc64le, and s390x. No CVSS score is provided in the advisory.
Potential Impact
The vulnerability allows denial of service (DoS) against the Kerberos authentication service by exploiting an integer underflow and out-of-bounds read. This could disrupt authentication processes relying on Kerberos, potentially impacting network security and availability of services that depend on it. There are no known exploits in the wild at this time.
Mitigation Recommendations
Red Hat has released updated krb5 packages for Red Hat Enterprise Linux 9.4 and related variants to address this vulnerability. Users should apply the official security update as described in Red Hat advisory RHSA-2026:24686 and the referenced update article (https://access.redhat.com/articles/11258). Applying these updates will remediate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:24686
- Cve Count
- 1
- Additional Cves
- []
- Cvss Version
- null
Threat ID: 6a27e9808dd33fbd85167aa3
Added to database: 6/9/2026, 10:22:56 AM
Last enriched: 6/9/2026, 10:24:05 AM
Last updated: 6/10/2026, 7:07:57 AM
Views: 4
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