Wasmtime is an open source runtime for WebAssembly. Wasmtime's implementation of WebAssembly tail calls combined with stack traces can result in a runtime crash in certain WebAssembly modules. The runtime crash may be undefined behavior if Wasmtime was compiled with Rust 1.80 or prior. The runtime crash is a deterministic process abort when Wasmtime is compiled with Rust 1.81 and later. WebAssembly tail calls are a proposal which relatively recently reached stage 4 in the standardization process. Wasmtime first enabled support for tail calls by default in Wasmtime 21.0.0, although that release contained a bug where it was only on-by-default for some configurations. In Wasmtime 22.0.0 tail calls were enabled by default for all configurations. The specific crash happens when an exported function in a WebAssembly module (or component) performs a return_call (or return_call_indirect or return_call_ref) to an imported host function which captures a stack trace (for example, the host function raises a trap). In this situation, the stack-walking code previously assumed there was always at least one WebAssembly frame on the stack but with tail calls that is no longer true. With the tail-call proposal it's possible to have an entry trampoline appear as if it directly called the exit trampoline. This situation triggers an internal assert in the stack-walking code which raises a Rust panic!(). When Wasmtime is compiled with Rust versions 1.80 and prior this means that an extern "C" function in Rust is raising a panic!(). This is technically undefined behavior and typically manifests as a process abort when the unwinder fails to unwind Cranelift-generated frames. When Wasmtime is compiled with Rust versions 1.81 and later this panic becomes a deterministic process abort. Overall the impact of this issue is that this is a denial-of-service vector where a malicious WebAssembly module or component can cause the host to crash. There is no other impact at this time other than availability of a service as the result of the crash is always a crash and no more. This issue was discovered by routine fuzzing performed by the Wasmtime project via Google's OSS-Fuzz infrastructure. We have no evidence that it has ever been exploited by an attacker in the wild. All versions of Wasmtime which have tail calls enabled by default have been patched: * 21.0.x - patched in 21.0.2 * 22.0.x - patched in 22.0.1 * 23.0.x - patched in 23.0.3 * 24.0.x - patched in 24.0.1 * 25.0.x - patched in 25.0.2. Wasmtime versions from 12.0.x (the first release with experimental tail call support) to 20.0.x (the last release with tail-calls off-by-default) have support for tail calls but the support is disabled by default. These versions are not affected in their default configurations, but users who explicitly enabled tail call support will need to either disable tail call support or upgrade to a patched version of Wasmtime. The main workaround for this issue is to disable tail support for tail calls in Wasmtime, for example with Config::wasm_tail_call(false). Users are otherwise encouraged to upgrade to patched versions.
CVE-2024-47763
“—” beside the score: it is equal to NVD's CVSS score.
Score 5.5 from GitHub Security Advisory (severity: MODERATE) published 2024-10-09. NVD baseline CVSS 5.5; sources differ by 0.0.
Also known asEUVD-2024-3109 (ENISA EUVD) · GHSA-q8hx-mm92-4wvg (GitHub Security Advisories)Source: ENISA EUVD
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 5.5
- EG Score
- 5.5MEDIUMmedium confidence
- EG Risk
- 25EG Risk 25/100
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)Severity55% × 45%Impact severity (EG Severity): CVSS 5.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.2% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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
- 0.2%
- EPSS %ILE
- 15th
- 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 (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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 9, 2024
Last Modified
September 29, 2025
References (6)
- security-advisories@githubhttps://docs.rs/wasmtime/latest/wasmtime/struct.Config.html#method.wasm_tail_callProduct
- security-advisories@githubhttps://github.com/WebAssembly/proposalsProduct
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/pull/8540Product
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/pull/8682Product
- security-advisories@githubhttps://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-q8hx-mm92-4wvgMitigation · Patch · Third Party Advisory
- security-advisories@githubhttps://github.com/webassembly/tail-callProduct
Vendor Advisories for CVE-2024-47763(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Patch Availability(5)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| rust | wasmtime @ 21.0.2 (fixes >= 12.0.0, < 21.0.2) | — | ghsa |
| rust | wasmtime @ 22.0.1 (fixes >= 22.0.0, < 22.0.1) | — | ghsa |
| rust | wasmtime @ 23.0.3 (fixes >= 23.0.0, < 23.0.3) | — | ghsa |
| rust | wasmtime @ 24.0.1 (fixes >= 24.0.0, < 24.0.1) | — | ghsa |
| rust | wasmtime @ 25.0.2 (fixes >= 25.0.0, < 25.0.2) | — | ghsa |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(4 across 4 ecosystems)
crates.io(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| wasmtime | — |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| rust-wasmtime | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| rust-wasmtime | — |
| — |
PyPI(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| wasmtime-bin | — |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 39× 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.
Showing the most recent 94 of 210 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 6 repeat rows among the latest 100 are merged into the row they repeat. The 116 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 16:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-11-01 08:11 UTCGHSA enrichmentGHSA-q8hx-mm92-4wvg · GitHub severity MODERATE · GitHub CVSS 5.5
- 2026-11-01 08:11 UTCEG score recompute
- 2026-10-31 16:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-30 16:32 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-29 16:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-28 16:29 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-27 16:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-26 16:29 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-25 17:00 UTCEG score recompute
- 2026-10-25 16:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-24 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-24 04:28 UTCEG score recompute
- 2026-10-23 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-22 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-21 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-20 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-19 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-18 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-18 06:57 UTCEG score recompute
- 2026-10-17 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-16 16:37 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-15 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-14 16:30 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-13 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
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- 2026-10-12 17:43 UTCEG score recompute
- 2026-10-12 16:31 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-11 21:09 UTCEG score recompute
- 2026-10-11 16:01 UTCEG score recompute
- 2026-10-11 13:46 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-10 19:58 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-10 12:25 UTCOSV refresh
- 2026-10-09 20:05 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-08 17:08 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-07 23:46 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-06 15:16 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-05 17:41 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-04 23:20 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-03 14:24 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-10-01 19:48 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-30 19:55 UTCEG score recompute
- 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-29 15:18 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-28 13:50 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-27 13:44 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-26 15:57 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-09-24 14:01 UTCEPSS rescoreEPSS 0.2% · 13th percentile
- 2026-09-23 13:46 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-22 14:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-20 21:56 UTCOSV refresh
- 2026-09-20 20:14 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-19 15:40 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-18 19:26 UTCEPSS rescoreEPSS 0.2% · 16th percentile
- 2026-09-17 19:27 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-16 14:06 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-16 05:12 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-15 03:08 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-13 16:45 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-12 14:59 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-11 14:51 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-11 09:35 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-10 09:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-08 21:58 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-07 16:00 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-06 13:46 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-04 13:59 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-04 05:05 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-02 14:10 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-01 21:27 UTCOSV refresh
- 2026-09-01 13:52 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-01 04:37 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-30 19:16 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-30 01:20 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-28 21:39 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-27 14:23 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-26 14:44 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-25 13:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-24 14:15 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-23 00:18 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-21 23:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-20 22:54 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-19 17:02 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-18 13:46 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-17 13:45 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-16 14:54 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-16 02:13 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-15 23:07 UTCOSV refresh
- 2026-08-15 01:29 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-13 21:59 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-12 13:49 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-11 13:40 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-10 23:58 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-09 13:45 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-08 16:35 UTCEPSS rescoreEPSS 0.2% · 15th percentile
Related CVEs(same product + same CWE)
Same product
10 shownPyPI:wasmtime-bin · Debian:13:rust-wasmtime
Frequently asked(5)
What is CVE-2024-47763?
When was the CVE record for CVE-2024-47763 published?
Is CVE-2024-47763 actively exploited?
What is the CVSS score of CVE-2024-47763?
How do I remediate CVE-2024-47763?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2024-47763
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