PT-2026-48636 · Red Hat · Red Hat Enterprise Linux 10+6

Published 2026-06-11 · Updated 2026-06-11 · CVE-2026-11850

Mitre

CVSS v3.1

5.0

Medium

Base vector

AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H

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.

Fix

Integer Underflow

Weakness Enumeration

CWE-191

Related Identifiers

CVE-2026-11850

Affected Products

Red Hat Enterprise Linux 10

Red Hat Enterprise Linux 6

Red Hat Enterprise Linux 7

Red Hat Enterprise Linux 8

Red Hat Enterprise Linux 9

Red Hat Hardened Images

Red Hat Openshift Container Platform 4

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-11850 · Security Note
• https://access.redhat.com/security/cve/CVE-2026-11850 · Note
• https://bugzilla.redhat.com/show_bug.cgi?id=2459970 · Note