CVE-2026-2069 — ggml-org llama.cpp GBNF Grammar llama-grammar.cpp llama_grammar_advance_stack stack-based overflow
A flaw has been found in ggml-org llama.cpp up to 55abc39. Impacted is the function llama_grammar_advance_stack of the file llama.cpp/src/llama-grammar.cpp of the component GBNF Grammar Handler. This manipulation causes stack-based buffer overflow. The attack needs to be launched locally. The exploit has been published and may be used. Patch name: 18993. To fix this issue, it is recommended to deploy a patch.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.1% (30-day exploitation probability)+0
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Ggml-org Llama.cpp).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 4.8 | CVSS 4.0 | Medium | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
| 1.9 | CVSS 4.0 | Low | — | — | cna@vuldb.com via NIST National Vulnerability Database |
| 3.3 | CVSS 3.1 | Low | 1.8 | 1.4 | cna@vuldb.com via NIST National Vulnerability Database |
| 3.3 | CVSS 3.1 | Low | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
| 3.3 | CVSS 3.0 | Low | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
| 1.7 | CVSS 2.0 | Low | 3.1 | 2.9 | cna@vuldb.com via NIST National Vulnerability Database |
| 1.7 | CVSS 2.0 | Low | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L (score shown at the top: cna@vuldb.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.15%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · ggml-org/llama.cpp
- SSVC assessment updated
- Record published
- CVSS changed · 3.3
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
8 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-107183 llama.cpp before b11393 Use-After-Free via common_chat_peg_mapper chat_parser 8d
- Medium CVE-2026-86317 ggml-org llama.cpp RPC Server ggml-rpc.cpp deserialize_tensor assertion Sep 7, 2026
- Medium CVE-2026-78148 ggml-org llama.cpp ggml-RPC Server ggml-rpc.cpp graph_compute null pointer dereference Aug 23, 2026
- High CVE-2026-78147 ggml-org llama.cpp ggml-RPC Server ggml-rpc.cpp deserialize_tensor deserialization Aug 23, 2026
- Medium CVE-2026-70639 llama.cpp b1886–b7445 Null Pointer Dereference DoS via llama-android.cpp Aug 6, 2026
- High CVE-2026-70638 llama.cpp b1886–b7445 Integer Overflow via new_1batch() in llama-android.cpp Aug 6, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-2069 is "ggml-org llama.cpp GBNF Grammar llama-grammar.cpp llama_grammar_advance_stack stack-based overflow", rated Low. It affects Llama.cpp (Ggml-org); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 3.3 describes technical severity. EPSS 0.15% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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