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.
CVE-2026-116816
HIGHPre-NVD 7.87.8Trending — 5 sources updated this week
EchelonGraph scoreHIGH confidence
“—” beside the score: it is equal to the CVSS score beside it.
Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-10-27. A secondary CVSS source baseline 7.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: GitHub Security Advisory, a secondary CVSS source
Also known asEUVD-2026-110569 (ENISA EUVD) · GHSA-3r8c-j789-2864 (GitHub Security Advisories)Source: ENISA EUVD
7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 7.8Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 7.8
- EG Score
- 7.8HIGHhigh confidence
- EG Risk
- 35EG Risk 35/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity78% × 45%Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0% × 40%No KEV listing, EG-KEV tier or EPSS when EchelonGraph scored this CVE.Automatability0% × 15%CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CVSS v4.0 confidentiality and integrity impact both High). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.1%
- EPSS %ILE
- 2nd
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.1% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CVSS v4.0 confidentiality and integrity impact both High). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CVSS v4.0 confidentiality and integrity impact both High). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
October 27, 2026
Last Modified
October 27, 2026
Advisory Details (6)
Auto-updated Oct 27, 2026Patch available. Sources: github_commit, github_pr, github_release.
Web page
llama.cpp b5899 before b10261 Heap Out-of-Bounds Write via plamo2 Tokenizer | Advisories | VulnCheck
https://www.vulncheck.com/advisories/llama-cpp-b5899-before-b10261-heap-out-of-bounds-write-via-plamo2-tokenizerGitHub release Patch Available
b10261
Patch available: ggml-org/llama.cpp b10261
https://github.com/ggml-org/llama.cpp/releases/tag/b10261GitHub pull request
vocab : validate plamo2 byte tokens
Fix merged in ggml-org/llama.cpp PR #26511 on 2026-08-04 — awaiting tagged release
https://github.com/ggml-org/llama.cpp/pull/26511GitHub pull request
vocab : fix heap OOB write in PLaMo-2 <0xNN> byte-token parsing
Upstream fix in progress (PR #25969 · ggml-org/llama.cpp, state=closed)
https://github.com/ggml-org/llama.cpp/pull/25969GitHub commit
commit cf06ad7dfe79 (ggml-org/llama.cpp)
Fix landed in ggml-org/llama.cpp commit cf06ad7dfe79 — awaiting tagged release
https://github.com/ggml-org/llama.cpp/commit/cf06ad7dfe79e7bf2934150d4fefe1ce8db05490Web page
llama.cpp/src/llama-vocab.cpp at b10259 · ggml-org/llama.cpp · GitHub
https://github.com/ggml-org/llama.cpp/blob/b10259/src/llama-vocab.cpp#L1376-L1377Vendor Advisories for CVE-2026-116816(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 7× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
- 2026-10-27 16:08 UTCEG score recompute
- 2026-10-27 16:08 UTCGHSA enrichmentGHSA-3r8c-j789-2864 · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-27 02:01 UTCENISA EUVD ID recordedEUVD-2026-110569 · Source: ENISA EUVD
- 2026-10-27 01:29 UTCEG score recompute
- 2026-10-27 01:12 UTCEG score recomputeFirst assessed: 7.8 HIGH
- 2026-10-27 01:10 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-116816?
CVE-2026-116816 is a high-severity vulnerability; its CVE record was published on October 27, 2026. 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 <0x-1> whose negative parsed value writes token ids before the bytes_…
When was CVE-2026-116816 made public?
CVE-2026-116816 was made public on July 21, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on October 27, 2026. EchelonGraph's copy of the record carries a last-modified date of October 27, 2026; the record at its source may have been updated since.
Is CVE-2026-116816 actively exploited?
CVE-2026-116816 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (2nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-116816?
CVE-2026-116816 has a CVSS base score of 7.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-116816?
A fix for CVE-2026-116816 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-116816 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-116816
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