In MIT Kerberos 5 (aka krb5) before 1.22.3, there is an integer underflow and resultant out-of-bounds read if an application calls…
MIT Kerberos 5 (krb5) versions before 1.22.3 contain an integer underflow vulnerability that leads to an out-of-bounds read when an application calls gss_accept_sec_context() on systems with a NegoEx mechanism registered. This flaw can be triggered by an unauthenticated remote attacker, potentially causing the affected process to terminate unexpectedly during message parsing.
AI Analysis
Technical Summary
An integer underflow and consequent out-of-bounds read exist in MIT Kerberos 5 (krb5) prior to version 1.22.3. The vulnerability occurs when gss_accept_sec_context() is called on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can exploit this to cause the process to terminate in the parse_message function, resulting in a denial of service.
Potential Impact
The vulnerability allows an unauthenticated remote attacker to cause a denial of service by triggering a process crash due to an out-of-bounds read. There is no indication of confidentiality or integrity impact from the provided data.
Mitigation Recommendations
A fix is available in MIT Kerberos 5 version 1.22.3. Users should upgrade to version 1.22.3 or later to remediate this vulnerability. Patch status is confirmed by the version boundary provided. No additional mitigations are indicated.
In MIT Kerberos 5 (aka krb5) before 1.22.3, there is an integer underflow and resultant out-of-bounds read if an application calls…
Description
MIT Kerberos 5 (krb5) versions before 1.22.3 contain an integer underflow vulnerability that leads to an out-of-bounds read when an application calls gss_accept_sec_context() on systems with a NegoEx mechanism registered. This flaw can be triggered by an unauthenticated remote attacker, potentially causing the affected process to terminate unexpectedly during message parsing.
CVSS v3.1
Score 5.9medium
Affected software
pkg:deb/ubuntu/[email protected]+dfsg-2ubuntu5.4+esm7?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/[email protected]+dfsg-5ubuntu2.2+esm7?arch=source&distro=esm-infra/xenialpkg:deb/ubuntu/[email protected]+esm5?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=focalpkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
An integer underflow and consequent out-of-bounds read exist in MIT Kerberos 5 (krb5) prior to version 1.22.3. The vulnerability occurs when gss_accept_sec_context() is called on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can exploit this to cause the process to terminate in the parse_message function, resulting in a denial of service.
Potential Impact
The vulnerability allows an unauthenticated remote attacker to cause a denial of service by triggering a process crash due to an out-of-bounds read. There is no indication of confidentiality or integrity impact from the provided data.
Mitigation Recommendations
A fix is available in MIT Kerberos 5 version 1.22.3. Users should upgrade to version 1.22.3 or later to remediate this vulnerability. Patch status is confirmed by the version boundary provided. No additional mitigations are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-40356
- Osv Schema Version
- 1.7.0
- Aliases
- []
- Ecosystems
- ["Ubuntu:Pro:14.04:LTS","Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:25.10","Ubuntu:26.04:LTS"]
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a6151199c2644c7f8da5c49
Added to database: 07/22/2026, 23:24:09 UTC
Last enriched: 07/22/2026, 23:51:40 UTC
Last updated: 07/31/2026, 19:24:47 UTC
Views: 5
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