CVE-2026-107183 llama.cpp before b11393 Use-After-Free via common_chat_peg_mapper chat_parser
Unauthenticated attackers can trigger a use-after-free in llama.cpp's chat parser via crafted requests, leading to heap corruption, crashes, or potential code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-107183?
CVE-2026-107183 is a critical use after free vulnerability in ggml-org llama.cpp, published on 7 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
llama.cpp before b11393 contains a use-after-free and double free vulnerability in common_chat_peg_mapper::map that allows unauthenticated remote attackers to corrupt heap memory via a dangling current_tool pointer. Attackers can submit a chat_parser in a POST /completion request emitting a tool-id after a tool-close tag to crash llama-server and shape a heap write primitive.
Weakness: CWE-416
Which versions are affected by CVE-2026-107183?
How do I fix CVE-2026-107183?
No fix has been published for CVE-2026-107183 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-107183 being exploited?
There is no known exploitation of CVE-2026-107183 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-107183, GHSA-3g9g-qh2j-c5q8, UBUNTU-CVE-2026-107183.