CVE-2026-11850
MEDIUM
MEDIUM
Priority: 0.01
BB Relevance:
45/100
Published: 2026-06-11
Modified: 2026-11-07
First seen: 2026-10-31
Status: active
Attack Surface
Network
No Interaction
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
High
UI:
None
S:
Unchanged
C:
Low
I:
None
A:
High
Description
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.
Weakness Classification (1)
References & Advisories (3)
vendor-advisory
x_refsource_REDHAT
vdb-entry
x_refsource_REDHAT
issue-tracking
x_refsource_REDHAT