Vulnerability · Published Jul 27, 2026 · Assigned by VulDB
CVE-2026-17501ggml-org llama.cpp JSON-Schema-to-GBNF Conversion json-schema-to-grammar.cpp transform recursion
Medium 5.3
In plain English
A medium-severity security flaw in llama.cpp from ggml-org. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities).
Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.7%top 45.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A flaw has been found in ggml-org llama.cpp e15efe0. This vulnerability affects the function transform of the file common/json-schema-to-grammar.cpp of the component JSON-Schema-to-GBNF Conversion. This manipulation causes uncontrolled recursion. The attack may be initiated remotely. The pull request to fix this issue awaits acceptance.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | llama.cpp | no fix listed | DEBIAN-CVE-2026-17501 |
| Ubuntu:26.04:LTS | llama.cpp | no fix listed | UBUNTU-CVE-2026-17501 |
| Ubuntu:26.10 | llama.cpp | no fix listed | UBUNTU-CVE-2026-17501 |
Affected products (as reported)
Weakness: CWE-674, CWE-404 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:X/RC:R
References
- VDB-383354 | ggml-org llama.cpp JSON-Schema-to-GBNF Conversion json-schema-to-grammar.cpp transform recursion vdb-entry, technical-description
- VDB-383354 | CTI Indicators (IOB, IOC, TTP, IOA) signature, permissions-required
- CVE-2026-17501 | CVE Analysis and Report third-party-advisory
- Submit #798504 | ggml-org llama.cpp (confirmed on commit e15efe0 / tag b8635+1) Uncontrolled Recursion third-party-advisory
- https://github.com/ggml-org/llama.cpp/issues/25283 issue-tracking
- https://github.com/ggml-org/llama.cpp/pull/25308 issue-tracking, patch
- https://github.com/ggml-org/llama.cpp/ product