7.5

CVE-2026-27572: bytecodealliance wasmtime

CVSS: 7.5v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-27572DEBIAN-CVE-2026-27572CGA-5c9m-m45c-2j2g
Published 24-02-2026Last modified 27-02-2026
Open JSON

Vulnerability summary

CVE-2026-27572 is a high (CVSS 7.5) vulnerability in bytecodealliance wasmtime. EPSS estimates a 0.68% chance of exploitation in the next 30 days, higher than 51.4% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
0.68%
0%100%
Low · +0.21 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-4C8Q-MJ8W-CJWX

Timeline

  1. 24-02-2026
    PublishedVulnerability first disclosed.
  2. 27-02-2026
    Last modifiedVulnerability information updated.

Description

Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of the `wasi:http/types.fields` resource is susceptible to panics when too many fields are added to the set of headers. Wasmtime's implementation in the `wasmtime-wasi-http` crate is backed by a data structure which panics when it reaches excessive capacity and this condition was not handled gracefully in Wasmtime. Panicking in a WASI implementation is a Denial of Service vector for embedders and is treated as a security vulnerability in Wasmtime. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 patch this vulnerability and return a trap to the guest instead of panicking. There are no known workarounds at this time. Embedders are encouraged to update to a patched version of Wasmtime.

CVSS metrics

9 scores · 7 sources · 2 versions

EPSS trend

Probability

0.68%

Chance of exploitation in the next 30 days

Percentile

51%

Versus all other CVEs

30-day change

+0.21 pp

From 0.47% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.68%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard6 products
  • washAll versions (No fix recorded)
  • wasmcloud< 2.0.1-r0
  • wizer< 10.0.0-r7
  • yara-x< 1.13.0-r2
  • zed< 0.228.0-r3
Wolfi6 products
  • washAll versions (No fix recorded)
  • wasmcloud< 2.0.1-r0
  • wizer< 10.0.0-r7
  • yara-x< 1.13.0-r2
  • zed< 0.228.0-r3
Bytecodealliance1 product
  • wasmtime< 24.0.6 | ≥ 25.0.0, < 36.0.6 | ≥ 37.0.0, < 40.0.4 | ≥ 41.0.0, < 41.0.4
Crates.Io1 product
  • wasmtime< 24.0.6 | ≥ 25.0.0, < 36.0.6 | ≥ 37.0.0, < 40.0.4 | ≥ 41.0.0, < 41.0.4
Debian1 product
  • rust-wasmtimeAll versions (No fix recorded) | < 36.0.6+dfsg-1
Ubuntu1 product
  • rust-wasmtimeAll versions (No fix recorded)

6 vendors · 16 products

References

15 links
Show all 15 references