CVE-2026-34983

MEDIUMNVD 5.05.0—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.0 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 98% of all CVEs by exploit prediction. 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).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
5.0EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.0Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Wasmtime is a runtime for WebAssembly. In 43.0.0, cloning a wasmtime::Linker is unsound and can result in use-after-free bugs. This bug is not controllable by guest Wasm programs. It can only be triggered by a specific sequence of embedder API calls made by the host. Specifically, the following steps must occur to trigger the bug clone a wasmtime::Linker, drop the original linker instance, use the new, cloned linker instance, resulting in a use-after-free. This vulnerability is fixed in 43.0.1.

CVSS v3
5.0
EG Score
5.0(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: Track

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 computed
Severity50% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

April 9, 2026

Last Modified

April 15, 2026

Advisory Details (1)

Auto-updated Aug 2, 2026
Patch available. Sources: github.
github Patch Available

Use-after-free bug after cloning `wasmtime::Linker` · Advisory · bytecodealliance/wasmtime · GitHub

https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hfr4-7c6c-48w2

Vendor Advisories for CVE-2026-34983(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
crates.io(1)
PackageVulnerable rangeFixed inDependents
wasmtime43.0.043.0.1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
rust-wasmtime26.0.1+dfsg-10 ... 36.0.9+dfsg-2 (43 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
rust-wasmtime26.0.1+dfsg-10 ... 36.0.6+dfsg-7 (34 versions)36.0.7+dfsg-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
wasmtime0.0.1 ... 9.0.0 (87 versions)——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 5× in last 7d / 31× 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.

Showing the most recent 100 of 123 total refreshes for this CVE.

  1. 2026-08-27 14:25 UTCEPSS rescore
  2. 2026-08-26 14:46 UTCEPSS rescore
  3. 2026-08-25 13:49 UTCEPSS rescore
  4. 2026-08-21 23:49 UTCEPSS rescore
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-19 17:03 UTCEPSS rescore
  7. 2026-08-17 13:47 UTCEPSS rescore
  8. 2026-08-16 14:56 UTCEPSS rescore
  9. 2026-08-16 07:09 UTCEG score recompute
  10. 2026-08-16 02:14 UTCEPSS rescore
  11. 2026-08-15 01:30 UTCEPSS rescore
  12. 2026-08-14 05:07 UTCEG score recompute
  13. 2026-08-13 22:00 UTCEPSS rescore
  14. 2026-08-12 19:24 UTCEG score recompute
  15. 2026-08-12 13:50 UTCEPSS rescore
  16. 2026-08-11 06:18 UTCEG score recompute
  17. 2026-08-11 00:00 UTCEPSS rescore
  18. 2026-08-09 04:34 UTCEG score recompute
  19. 2026-08-08 16:37 UTCEPSS rescore
  20. 2026-08-07 14:26 UTCEG score recompute
  21. 2026-08-06 13:46 UTCEPSS rescore
  22. 2026-08-05 23:45 UTCEG score recompute
  23. 2026-08-05 19:17 UTCEPSS rescore
  24. 2026-08-04 15:10 UTCEPSS rescore
  25. 2026-08-04 10:38 UTCEPSS rescore
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  1. 2026-08-03 22:00 UTCEG score recompute
  2. 2026-08-03 10:36 UTCEPSS rescore
  3. 2026-08-02 13:54 UTCEG score recompute
  4. 2026-08-02 02:27 UTCEPSS rescore
  5. 2026-08-01 04:16 UTCEPSS rescore
  6. 2026-07-30 01:30 UTCEPSS rescore
  7. 2026-07-27 14:13 UTCEPSS rescore
  8. 2026-07-25 14:18 UTCEPSS rescore
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  10. 2026-07-24 14:17 UTCEPSS rescore
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  12. 2026-07-23 14:18 UTCEPSS rescore
  13. 2026-07-23 14:18 UTCEPSS rescore
  14. 2026-07-23 03:10 UTCEG score recompute
  15. 2026-07-22 14:08 UTCEPSS rescore
  16. 2026-07-21 15:24 UTCEPSS rescore
  17. 2026-07-20 20:32 UTCOSV refresh
  18. 2026-07-20 17:08 UTCEPSS rescore
  19. 2026-07-19 14:31 UTCEPSS rescore
  20. 2026-07-19 02:29 UTCEPSS rescore
  21. 2026-07-18 10:04 UTCEPSS rescore
  22. 2026-07-16 17:03 UTCEPSS rescore
  23. 2026-07-15 16:57 UTCEPSS rescore
  24. 2026-07-15 16:57 UTCEPSS rescore
  25. 2026-07-15 02:00 UTCEPSS rescore
  26. 2026-07-13 22:30 UTCEPSS rescore
  27. 2026-07-13 06:13 UTCEPSS rescore
  28. 2026-07-13 06:13 UTCEPSS rescore
  29. 2026-07-12 05:46 UTCEPSS rescore
  30. 2026-07-09 19:10 UTCEPSS rescore
  31. 2026-07-08 15:15 UTCEPSS rescore
  32. 2026-07-07 13:46 UTCEPSS rescore
  33. 2026-07-06 16:27 UTCEPSS rescore
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  35. 2026-07-06 02:23 UTCEPSS rescore
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  37. 2026-07-05 02:30 UTCEPSS rescore
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  39. 2026-07-01 15:06 UTCEPSS rescore
  40. 2026-06-30 23:22 UTCEPSS rescore
  41. 2026-06-29 14:06 UTCEPSS rescore
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  43. 2026-06-28 14:07 UTCEPSS rescore
  44. 2026-06-28 14:07 UTCEPSS rescore
  45. 2026-06-27 03:08 UTCEPSS rescore
  46. 2026-06-25 13:49 UTCEPSS rescore
  47. 2026-06-25 13:49 UTCEPSS rescore
  48. 2026-06-24 14:05 UTCEPSS rescore
  49. 2026-06-23 21:33 UTCEPSS rescore
  50. 2026-06-23 21:33 UTCEPSS rescore
  51. 2026-06-22 14:25 UTCEPSS rescore
  52. 2026-06-22 14:25 UTCEPSS rescore
  53. 2026-06-21 14:56 UTCEPSS rescore
  54. 2026-06-21 14:56 UTCEPSS rescore
  55. 2026-06-21 01:59 UTCEPSS rescore
  56. 2026-06-19 19:25 UTCEPSS rescore
  57. 2026-06-19 19:25 UTCEPSS rescore
  58. 2026-06-18 17:52 UTCEPSS rescore
  59. 2026-06-18 17:52 UTCEPSS rescore
  60. 2026-06-17 17:53 UTCEPSS rescore
  61. 2026-06-16 17:52 UTCEPSS rescore
  62. 2026-06-15 17:49 UTCEPSS rescore
  63. 2026-06-14 23:18 UTCEPSS rescore
  64. 2026-06-12 23:12 UTCEPSS rescore
  65. 2026-06-12 23:12 UTCEPSS rescore
  66. 2026-06-11 14:00 UTCEPSS rescore
  67. 2026-06-10 22:18 UTCEPSS rescore
  68. 2026-06-10 13:22 UTCEPSS rescore
  69. 2026-06-07 15:25 UTCEPSS rescore
  70. 2026-06-07 15:25 UTCEPSS rescore
  71. 2026-06-07 15:25 UTCEPSS rescore
  72. 2026-06-06 13:47 UTCEPSS rescore
  73. 2026-06-06 13:47 UTCEPSS rescore
  74. 2026-06-05 22:47 UTCEPSS rescore
  75. 2026-06-05 22:47 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-34983?
CVE-2026-34983 is a medium vulnerability published on April 9, 2026. Wasmtime is a runtime for WebAssembly. In 43.0.0, cloning a wasmtime::Linker is unsound and can result in use-after-free bugs. This bug is not controllable by guest Wasm programs. It can only be triggered by a specific sequence of embedder API calls made by the host. Specifically, the following…
When was CVE-2026-34983 disclosed?
CVE-2026-34983 was first published in the National Vulnerability Database on April 9, 2026, with the most recent update on April 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-34983 actively exploited?
CVE-2026-34983 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 98.2% of all scored CVEs.
What is the CVSS score of CVE-2026-34983?
CVE-2026-34983 has a CVSS v3 base score of 5.0 (NVD).
How do I remediate CVE-2026-34983?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-34983, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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