Apache HTTP Server <=2.4.66 Null-Termination OOB Read
CVE-2026-34032 Published on May 4, 2026

Apache HTTP Server: mod_proxy_ajp: Heap Buffer Over-Read Due to Missing Null-Termination Check (ajp_msg_get_string)
Improper Null Termination, Out-of-bounds Read vulnerability in Apache HTTP Server. This issue affects Apache HTTP Server: through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-34032 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.

Attack Vector:

NETWORK

Attack Complexity:

LOW

Privileges Required:

NONE

User Interaction:

NONE

Scope:

UNCHANGED

Confidentiality Impact:

LOW

Integrity Impact:

NONE

Availability Impact:

NONE

Timeline

2026-03-01

Report received

2026-05-04

fixed in 2.4.x by r1933343 64 days later.

Weakness Types

Improper Null Termination

The software does not terminate or incorrectly terminates a string or array with a null character or equivalent terminator. Null termination errors frequently occur in two different ways. An off-by-one error could cause a null to be written out of bounds, leading to an overflow. Or, a program could use a strncpy() function call incorrectly, which prevents a null terminator from being added at all. Other scenarios are possible.

Out-of-bounds Read

The software reads data past the end, or before the beginning, of the intended buffer. Typically, this can allow attackers to read sensitive information from other memory locations or cause a crash. A crash can occur when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string. The expected sentinel might not be located in the out-of-bounds memory, causing excessive data to be read, leading to a segmentation fault or a buffer overflow. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent read operation then produces undefined or unexpected results.