What’s Vulnerable › Vulnerabilities

CVE-2026-116816: llama.cpp b5899 before b10261 Heap Out-of-Bounds Write via plamo2 Tokenizer

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-27 · updated 2026-10-31
• Weakness: CWE-129

Description

llama.cpp b5899 before b10261 contains a heap out-of-bounds write vulnerability in llm_tokenizer_plamo2::build that allows attackers to corrupt heap memory via crafted GGUF models. Attackers can supply BYTE-typed token text like <0x-1> whose negative parsed value writes token ids before the bytes_ buffer during model loading, causing crashes or potential code execution.

Affected products

• ggml-org llama.cpp: from b5899 before b10261 — fixed in b10261

How to fix

Upgrade to a fixed version: ggml-org llama.cpp b10261. Check the vendor advisory for mitigations.

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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