Is CVE-2026-52132 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-52132 being exploited in the wild.

How severe is CVE-2026-52132?

High severity, with a CVSS score of 7.5, published 1 September 2026.

Which products and versions are affected?

GGML Llama.Cpp through commit 97f06e9.

Is there a fix for CVE-2026-52132?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-52132 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-52132?

Check whether you run GGML Llama.Cpp at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-52132: llama.cpp denial of service via negative top_n in reranking API

CVE-2026-52132 · Severity: high · CVSS 7.5 · Published 2026-09-01

llama.cpp is a C++ framework for running large language model inference. When started with the --reranking flag to enable document reranking functionality, the API fails to validate input parameters and crashes on malformed requests. A remote attacker can send a specially crafted POST request with a negative "top_n" value to cause the service to return HTTP 500 errors and exhaust memory, making the inference service unavailable to legitimate users.

Technologies: GGML Llama.Cpp. Vendors: GGML.

Quick answers

Is CVE-2026-52132 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-52132 being exploited in the wild.
How severe is CVE-2026-52132?: High severity, with a CVSS score of 7.5, published 1 September 2026.
Which products and versions are affected?: GGML Llama.Cpp through commit 97f06e9.
Is there a fix for CVE-2026-52132?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-52132 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-52132?: Check whether you run GGML Llama.Cpp at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is an integer handling error (CWE-190) in the /rerank endpoint handler, specifically in tools/server/server-context.cpp (line 4048) where the top_n parameter is extracted from the JSON request body without validation. When a negative top_n value is passed, it triggers a std::bad_alloc exception in the memory allocation routines of format_response_rerank (tools/server/server-common.cpp, line 1245), causing the server to return HTTP 500 errors. The attack requires the server to be explicitly started with the --reranking flag (not enabled by default) and network access to the HTTP API endpoint. The vulnerability is 100% reproducible with negative top_n values and causes denial of service through repeated crashes, though the server process survives individual incidents. No patch has been released as of the latest stable version.

Affected products

ggml llama.cpp through commit 97f06e9

Timeline

2026-08-12: disclosed
2026-09-01: advisory: Published to NVD

References

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