CVE-2026-40356

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Source
https://cve.org/CVERecord?id=CVE-2026-40356
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-40356.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-40356
Downstream
AZL (1)
BELL (1)
DEBIAN (1)
ECHO (1)
JLSEC (1)
MGASA (1)
OESA (1)
openSUSE (2)
RHSA (7)
RLSA (3)
ROOT (2)
SUSE (7)
UBUNTU (1)
Related
ALSA (3)
openSUSE (2)
SUSE (7)
Published
2026-04-28T00:00:00Z
Modified
2026-08-18T18:48:50Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

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 gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message.

Database specific 
{
    "cna_assigner": "mitre",
    "cwe_ids": [
        "CWE-191"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40356.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "1.18"
                },
                {
                    "fixed": "1.22.3"
                }
            ],
            "source": "AFFECTED_FIELD"
        },
        {
            "extracted_events": [
                {
                    "introduced": "1.18"
                },
                {
                    "fixed": "1.22.3"
                }
            ],
            "source": "CPE_FIELD"
        },
        {
            "extracted_events": [
                {
                    "fixed": "1.22.3"
                }
            ],
            "source": "DESCRIPTION"
        }
    ]
}
References

Affected packages

Git / github.com/krb5/krb5

Affected ranges

Type
GIT
Repo
https://github.com/krb5/krb5
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
2e75f0d9362fb979f5fc92829431a590a130929f
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:mit:kerberos_5:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "1.18.0"
        },
        {
            "last_affected": "1.22.2"
        }
    ],
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-40356.json"
vanir_signatures 
[
    {
        "deprecated": false,
        "digest": {
            "function_hash": "142762992336514430865573446923858023953",
            "length": 1059
        },
        "id": "CVE-2026-40356-0d8c4b90",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f",
        "target": {
            "file": "src/lib/gssapi/spnego/negoex_util.c",
            "function": "parse_nego_message"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "line_hashes": [
                "40952602198558450187255405215139956686",
                "188683493495594530274596671268481475985",
                "166540009649839522164965351439044043758",
                "38887152117437256870742115587696304902",
                "211427320194663522795255588816265163872",
                "157791089749722385199311103137710402737",
                "175049674007297452272386585316915970498",
                "125706769889133001570824185629183380644"
            ],
            "threshold": 0.9
        },
        "id": "CVE-2026-40356-575ea1f8",
        "signature_type": "Line",
        "signature_version": "v1",
        "source": "https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f",
        "target": {
            "file": "src/lib/gssapi/spnego/negoex_util.c"
        }
    },
    {
        "deprecated": false,
        "digest": {
            "function_hash": "250685795234022013172144621242627026091",
            "length": 1843
        },
        "id": "CVE-2026-40356-e36857fc",
        "signature_type": "Function",
        "signature_version": "v1",
        "source": "https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f",
        "target": {
            "file": "src/lib/gssapi/spnego/negoex_util.c",
            "function": "parse_message"
        }
    }
]
vanir_signatures_modified 
"2026-08-18T18:48:50Z"