CVE-2026-21869

Ggml Llama.cpp remote code execution

8.8 HIGHPublic exploitEPSS 0.53%

Published7 Jan 2026

Description

llama.cpp is an inference of several LLM models in C/C++. In commits 55d4206c8 and prior, the n_discard parameter is parsed directly from JSON input in the llama.cpp server's completion endpoints without validation to ensure it's non-negative. When a negative value is supplied and the context fills up, llama_memory_seq_rm/add receives a reversed range and negative offset, causing out-of-bounds memory writes in the token evaluation loop. This deterministic memory corruption can crash the process or enable remote code execution (RCE). There is no fix at the time of publication.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionRequired

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Ggml Llama.cppall versions

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

Patch & vendor advisories

https://github.com/ggml-org/llama.cpp/security/advisories/GHSA-8947-pfff-2f3c

References

https://github.com/ggml-org/llama.cpp/security/advisories/GHSA-8947-pfff-2f3cExploitVendor Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-21869 being actively exploited?

CVE-2026-21869 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.53%.

How severe is CVE-2026-21869?

CVE-2026-21869 has a CVSS 3.1 base score of 8.8, rated high. EPSS estimates a 0.53% probability of exploitation.

Which products are affected by CVE-2026-21869?

Affected products include Ggml Llama.cpp.

How do I fix CVE-2026-21869?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-21869 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation works Book a demo

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.