Wasmtime is a runtime for WebAssembly. From 46.0.0 until 46.0.2 and 47.0.3, fuel and epoch preemption checks inside bulk operations including memory.copy, table.grow, and array.copy can expose invalid intermediate state when an embedder mutates a Store in Store::epoch_deadline_callback or continues using a Store after cancellation or a trap. A cancelled non-nullable table growth can leave null elements, linear-memory growth during memory.copy can invalidate retained raw pointers, and callback-triggered garbage collection during array.copy can invalidate GC pointers, resulting in a crash, invalid memory access, or GC heap corruption. Embeddings whose callbacks only access the host data in Store, and embeddings that discard a Store after timeout or epoch deadline, are not affected. This issue is fixed in versions 46.0.2 and 47.0.3.
CVE-2026-104855
This low-severity CVE scores 2.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 2.0
- EG Score
- 2.0LOWlow confidence
- EG Risk
- 14EG Risk 14/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity20% × 45%Exploitation0% × 40%Automatability30% × 15%CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.3%
- EPSS %ILE
- 18th
- KEV
- Not listed
CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 2, 2026
Last Modified
October 2, 2026
References (9)
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/commit/3ebfbe5af4927c157d6fcaca42b8dbb6d17b73fb
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/commit/99b0bc39d447317a4102c056081c83a9a84a46e0
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/commit/a3eb27af01ba5a30320a90ea1405059cdfedd353
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/pull/14041
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/pull/14043
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/pull/14045
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/releases/tag/v46.0.2
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/releases/tag/v47.0.3
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-2hw9-mc66-jc2q
Vendor Advisories for CVE-2026-104855(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
crates.io(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| wasmtime | — | 46.0.2 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 4× in last 7d / 4× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.
- 2026-10-03 14:25 UTCEPSS rescore
- 2026-10-02 18:19 UTCEG score recompute
- 2026-10-02 17:47 UTCEG score recompute
- 2026-10-02 17:45 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same CWE)
Same product
10 showncrates.io:wasmtime
Frequently asked(5)
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Dependency Blast Radius
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