Integer overflow in Bytecodealliance Wasmtime
CVE-2026-119131
Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a denial of service vulnerability in wasmtime-wasi-http that lets guests crash the host by sending long request URLs. Guests can use set-path-with-query with a '?' after byte 65535, overflowing a u16 index in the http crate and triggering a host panic.
Vulnerability class: Integer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-w36r-2hch-9xp9 (vendor-advisory)
- www.vulncheck.com/advisories/wasmtime-46.0.0-before-48.0.6-and-49.0.0-before-49… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-119131?
- CVE-2026-119131 is a medium-severity vulnerability in Bytecodealliance Wasmtime, classified under Integer Overflow or Wraparound. CVSS score: 5.3/10. Published 2026-10-29.
- How severe is CVE-2026-119131?
- Medium severity. CVSS v3 base score is 5.3 out of 10.