Integer Underflow Affecting krb5-server package, versions *


Severity

Recommended
0.0
medium
0
10

Based on CentOS security rating.

Threat Intelligence

EPSS
0.26% (18th percentile)

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  • Snyk IDSNYK-CENTOS6-KRB5SERVER-17327857
  • published12 Jun 2026
  • disclosed10 Jun 2026

Introduced: 10 Jun 2026

CVE-2026-11850  (opens in a new tab)
CWE-191  (opens in a new tab)

How to fix?

There is no fixed version for Centos:6 krb5-server.

NVD Description

Note: Versions mentioned in the description apply only to the upstream krb5-server package and not the krb5-server package as distributed by Centos. See How to fix? for Centos:6 relevant fixed versions and status.

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. 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.

CVSS Base Scores

version 3.1