GDB remote protocol stack buffer overflow (CVE-2026-121994)
CVE-2026-121994 Published on November 5, 2026

Gdb: gdb: stack buffer overflow in fetch_register_using_p via unchecked p-reply length
A stack buffer overflow in the GDB client's remote protocol handler allows an attacker-controlled debug target to execute arbitrary code in the GDB process. The vulnerability exists in fetch_register_using_p, which decodes a stub's register reply into an alloca-sized buffer without bounding writes by the register width.

NVD

Vulnerability Analysis

CVE-2026-121994 is exploitable with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Exploitation:
NONE
Automatable:
NO
Technical Impact:
TOTAL
Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Timeline

Reported to Red Hat.

Made public. 15 days later.

Weakness Type

What is a Stack Overflow Vulnerability?

A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

CVE-2026-121994 has been classified to as a Stack Overflow vulnerability or weakness.


Products Associated with CVE-2026-121994

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Red Hat Enterprise Linux (RHEL)
Red Hat Rhel Els
Red Hat Hummingbird

Affected Versions

Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux 9: Red Hat Hardened Images: