CVE-2026-115889

CRITICALPre-NVD 9.99.9
EchelonGraph scoreHIGH confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 9.9 from GitHub Security Advisory (severity: CRITICAL) published 2026-10-23. A secondary CVSS source baseline 9.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source

Also known asEUVD-2026-109186 (ENISA EUVD) · GHSA-897f-g5gm-fmxm (GitHub Security Advisories) · RUSTSEC-2026-0380 (OSV.dev)Source: ENISA EUVD

9.9EG
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: 0.5%CVSS: 9.9Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with many SSA values. The overflow can make Cranelift reference incorrect IR values, causing arbitrary miscompilation, type confusion, and other attacker-controlled effects that may escape the Wasm sandbox on any architecture using the default Cranelift backend. This issue is fixed in versions 36.0.19 and 43.0.0.

CVSS v3
9.9
EG Score
9.9CRITICALhigh confidence
EG Risk
45
EG Risk 45/100

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)
Severity99% × 45%
Impact severity (EG Severity): CVSS 9.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 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 low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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
0.5%
EPSS %ILE
39th
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 (9.9): severity, escalated by confirmed exploitation. This CVE's 9.9 is its impact severity (EG Severity), not escalated.

EG Severity
9.9 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-13). 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, and whom BOD 26-04 binds: 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 (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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)14 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 total (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 23, 2026

Last Modified

October 26, 2026

Advisory Details (7)

Auto-updated Nov 2, 2026
Patch available. Sources: github_pr, github_release, github, github_commit.
GitHub advisoryMentions a patch (unverified)

Bit-packing in Cranelift compiler causes silent overflow and miscompilation · Advisory · bytecodealliance/wasmtime · GitHub

https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-897f-g5gm-fmxm
GitHub release Patch Available

Release v43.0.0 (bytecodealliance/wasmtime)

Patch available: bytecodealliance/wasmtime v43.0.0

https://github.com/bytecodealliance/wasmtime/releases/tag/v43.0.0
GitHub release Patch Available

Release v36.0.19 (bytecodealliance/wasmtime)

Patch available: bytecodealliance/wasmtime v36.0.19

https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19
GitHub pull request

Security fixes for release 36.0.19

Fix merged in bytecodealliance/wasmtime PR #14818 on 2026-10-19 — awaiting tagged release

https://github.com/bytecodealliance/wasmtime/pull/14818
GitHub pull request

Cranelift: update ValueDataPacked to support full Value range.

Fix merged in bytecodealliance/wasmtime PR #12613 on 2026-02-18 — awaiting tagged release

https://github.com/bytecodealliance/wasmtime/pull/12613
GitHub commit

commit f517bd6e890c (bytecodealliance/wasmtime)

Fix landed in bytecodealliance/wasmtime commit f517bd6e890c — awaiting tagged release

https://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa
GitHub commit

commit ba8f7d70caa1 (bytecodealliance/wasmtime)

Fix landed in bytecodealliance/wasmtime commit ba8f7d70caa1 — awaiting tagged release

https://github.com/bytecodealliance/wasmtime/commit/ba8f7d70caa1825b7f64fa75cd9d03f4a438dae0

Vendor Advisories for CVE-2026-115889(2)

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

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
rustwasmtime @ 36.0.19 (fixes < 36.0.19)—ghsa
rustwasmtime @ 43.0.0 (fixes >= 37.0.0, < 43.0.0)—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

(3 across 3 ecosystems)
crates.io(1)
PackageVulnerable rangeFix by version rangeDependents
wasmtime—
  • every version up to 36.0.19: fixed in 36.0.19
  • 37.0.0 up to 43.0.0: fixed in 43.0.0
  • 0.0.0-0 up to 36.0.19: fixed in 36.0.19
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
rust-wasmtime26.0.1+dfsg-10 ... 36.0.9+dfsg-2 (44 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
rust-wasmtime26.0.1+dfsg-10 ... 36.0.9+dfsg-2 (43 versions)
  • every version up to 36.0.20+dfsg-1: fixed in 36.0.20+dfsg-1
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 17× in last 7d / 49× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

  1. 2026-11-13 19:52 UTCEchelonGraph re-scored
  2. 2026-11-13 19:52 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  3. 2026-11-13 16:50 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  4. 2026-11-12 18:34 UTCEchelonGraph re-scored
  5. 2026-11-12 18:34 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  6. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  7. 2026-11-11 18:36 UTCEchelonGraph re-scored
  8. 2026-11-11 18:36 UTCVendor advisory
  9. 2026-11-11 18:36 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  10. 2026-11-11 16:38 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  11. 2026-11-10 18:39 UTCEchelonGraph re-scored
  12. 2026-11-10 18:39 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  13. 2026-11-10 16:42 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  14. 2026-11-09 18:30 UTCEchelonGraph re-scored
  15. 2026-11-09 18:30 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  16. 2026-11-09 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  17. 2026-11-08 18:33 UTCEchelonGraph re-scored
  18. 2026-11-08 18:33 UTCVendor advisory
  19. 2026-11-08 18:33 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  20. 2026-11-08 16:38 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  21. 2026-11-07 18:36 UTCEchelonGraph re-scored
  22. 2026-11-07 18:36 UTCVendor advisory
  23. 2026-11-07 18:36 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  24. 2026-11-07 16:38 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  25. 2026-11-06 18:38 UTCEchelonGraph re-scored
Show 50 more
  1. 2026-11-06 18:38 UTCVendor advisory
  2. 2026-11-06 18:38 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  3. 2026-11-06 16:36 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  4. 2026-11-05 23:25 UTCOSV refresh
  5. 2026-11-05 18:40 UTCEchelonGraph re-scored
  6. 2026-11-05 18:40 UTCVendor advisory
  7. 2026-11-05 18:40 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  8. 2026-11-05 16:36 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  9. 2026-11-04 18:43 UTCEchelonGraph re-scored
  10. 2026-11-04 18:43 UTCVendor advisory
  11. 2026-11-04 18:43 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  12. 2026-11-04 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  13. 2026-11-03 18:45 UTCEchelonGraph re-scored
  14. 2026-11-03 18:45 UTCVendor advisory
  15. 2026-11-03 18:45 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  16. 2026-11-03 16:46 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  17. 2026-11-02 18:48 UTCEchelonGraph re-scored
  18. 2026-11-02 18:48 UTCVendor advisory
  19. 2026-11-02 18:48 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  20. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  21. 2026-11-01 18:50 UTCEchelonGraph re-scored
  22. 2026-11-01 18:50 UTCVendor advisory
  23. 2026-11-01 18:50 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  24. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  25. 2026-11-01 07:59 UTCGHSA enrichmentGHSA-897f-g5gm-fmxm · GitHub severity CRITICAL · GitHub CVSS 9.9
  26. 2026-11-01 07:59 UTCEchelonGraph re-scored
  27. 2026-10-31 18:53 UTCEchelonGraph re-scored
  28. 2026-10-31 18:53 UTCVendor advisory
  29. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  30. 2026-10-30 18:55 UTCEchelonGraph re-scored
  31. 2026-10-30 18:55 UTCVendor advisory
  32. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  33. 2026-10-29 18:58 UTCEchelonGraph re-scored
  34. 2026-10-29 18:58 UTCVendor advisory
  35. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  36. 2026-10-28 19:01 UTCEchelonGraph re-scored
  37. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  38. 2026-10-27 18:28 UTCEchelonGraph re-scored
  39. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  40. 2026-10-26 18:30 UTCEchelonGraph re-scored
  41. 2026-10-26 17:47 UTCEchelonGraph re-scored
  42. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  43. 2026-10-25 22:23 UTCEchelonGraph re-scored
  44. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  45. 2026-10-25 14:50 UTCEchelonGraph re-scored
  46. 2026-10-24 22:25 UTCEchelonGraph re-scored
  47. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  48. 2026-10-23 22:28 UTCEchelonGraph re-scored
  49. 2026-10-23 21:35 UTCEchelonGraph re-scoredFirst assessed: 9.9 CRITICAL
  50. 2026-10-23 21:34 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-115889?
CVE-2026-115889 is a critical-severity vulnerability; its CVE record was published on October 23, 2026. Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with many SSA values. The overflow can make…
When was the CVE record for CVE-2026-115889 published?
The CVE record for CVE-2026-115889 was published on October 23, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 26, 2026; the record at its source may have been updated since.
Is CVE-2026-115889 actively exploited?
CVE-2026-115889 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-115889?
CVE-2026-115889 has a CVSS base score of 9.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-115889?
A fix for CVE-2026-115889 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-115889 are linked in the Vendor Advisories panel on this page.

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