GHSA-85RQ-MQR4-HJW7
Vulnerability from github – Published: 2026-06-11 12:32 – Updated: 2026-06-12 15:30An integer underflow vulnerability was found in MIT krb5 in the berval2tl_data() function in plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c. The function performs an unsigned subtraction (bv_len - 2) without a prior bounds check. When bv_len is 0 or 1, the subtraction wraps to a large value which is then truncated to uint16_t, yielding 0xFFFE (65534) or 0xFFFF (65535). The subsequent malloc succeeds and memcpy reads up to 65534 bytes from a 0-1 byte buffer, resulting in a heap out-of-bounds read. The attack vector involves a malicious or compromised LDAP KDB backend returning a krbExtraData attribute with bv_len < 2, triggering the underflow when the KDC or kadmind reads principal data.
{
"affected": [],
"aliases": [
"CVE-2026-11850"
],
"database_specific": {
"cwe_ids": [
"CWE-191"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-11T10:16:21Z",
"severity": "MODERATE"
},
"details": "An integer underflow vulnerability was found in MIT krb5 in the berval2tl_data() function in plugins/kdb/ldap/libkdb_ldap/ldap_principal2.c. The function performs an unsigned subtraction (bv_len - 2) without a prior bounds check. When bv_len is 0 or 1, the subtraction wraps to a large value which is then truncated to uint16_t, yielding 0xFFFE (65534) or 0xFFFF (65535). The subsequent malloc succeeds and memcpy reads up to 65534 bytes from a 0-1 byte buffer, resulting in a heap out-of-bounds read.\nThe attack vector involves a malicious or compromised LDAP KDB backend returning a krbExtraData attribute with bv_len \u003c 2, triggering the underflow when the KDC or kadmind reads principal data.",
"id": "GHSA-85rq-mqr4-hjw7",
"modified": "2026-06-12T15:30:31Z",
"published": "2026-06-11T12:32:43Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-11850"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2026:25520"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2026-11850"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2459970"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.