SecuriTricks - CVE-2026-11850

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.

Product(s) Impacted

Vendor	Product	Versions
Mit	Krb5	*

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-191

Integer Underflow (Wrap or Wraparound)

The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	mit	krb5	/	/	/	/	/	/	/	/

References

https://access.redhat.com/security/cve/CVE-2026-11850

https://bugzilla.redhat.com/show_bug.cgi?id=2459970

CVSS Score

5.0 / 10

CVSS Data - 3.1

Attack Vector: NETWORK
Attack Complexity: HIGH
Privileges Required: HIGH
Scope: UNCHANGED
Confidentiality Impact: LOW
Integrity Impact: NONE
Availability Impact: HIGH

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H

View Vector String

Timeline

Published: June 11, 2026, 10:16 a.m.
Last Modified: June 11, 2026, 10:16 a.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

CVE-2026-11850