Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Red Hat / Red Hat Hardened Images | unaffected 1.22.2-8.hum1 before * |
| Red Hat / Red Hat Enterprise Linux 10 | affected |
| Red Hat / Red Hat Enterprise Linux 6 | affected |
| Red Hat / Red Hat Enterprise Linux 7 | affected |
| Red Hat / Red Hat Enterprise Linux 8 | affected |
| Red Hat / Red Hat Enterprise Linux 9 | affected |
| Red Hat / Red Hat OpenShift Container Platform 4 | affected |
| Red Hat / Red Hat OpenShift Container Platform 4 | affected |
CWE
CWE-191
References
- https://access.redhat.com/errata/RHSA-2026:25520
- https://access.redhat.com/security/cve/CVE-2026-11850
- https://bugzilla.redhat.com/show_bug.cgi?id=2459970
ADP enrichment
No English description supplied.
No references supplied.