llama.cpp b5899 before b10261 contains a heap out-of-bounds write vulnerability in llmtokenizerplamo2::build that allows attackers to…
CVE-2026-116816
llama.cpp b5899 before b10261 contains a heap out-of-bounds write vulnerability in llmtokenizerplamo2::build that allows attackers to corrupt heap memory via crafted GGUF models. Attackers can supply BYTE-typed token text like whose negative parsed value writes token ids before the bytes buffer during model loading, causing crashes or potential code execution.
Part of the AI stack
This affects GGUF, llama.cpp, in Inference & serving, Runtimes & formats.
Assessment
- CVSS
- 8.5 (v4.0)
- Severity
- High
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 27 October 2026
- Last updated
- 31 October 2026
- Weakness
- CWE-129
- Assigner
- disclosure@vulncheck.com
CVSS vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
At the source
References
- https://github.com/ggml-org/llama.cpp/blob/b10259/src/llama-vocab.cpp#L1376-L1377
- https://github.com/ggml-org/llama.cpp/commit/cf06ad7dfe79e7bf2934150d4fefe1ce8db05490
- https://github.com/ggml-org/llama.cpp/pull/25969
- https://github.com/ggml-org/llama.cpp/pull/26511
- https://github.com/ggml-org/llama.cpp/releases/tag/b10261
- https://www.vulncheck.com/advisories/llama-cpp-b5899-before-b10261-heap-out-of-bounds-write-via-plamo2-tokenizer
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