CVE-2026-119133

Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Misaligned VMContext via Exception Tags

2.1 LowFix available

Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in VMContext layout that causes undefined behavior when modules contain an odd number of exception tags. A WebAssembly module with an odd tag count misaligns subsequent host fields in embedders with exceptions enabled, although no exploitation path is currently known.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: Low
User interaction: Passive

What an attacker can affect

Confidentiality: None
Integrity: Low
Availability: None

Exploit likelihood

0.21%Unchanged since Oct 30, 2026

What each source reports

CVE List Score used 2.1

Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Misaligned VMContext via Exception Tags

Record: CVE-2026-119133
CVSS 4.0: 2.1 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS 3.1: 2.6 LowCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N
Weakness: CWE-758
Updated: 2026-11-02

EUVDEUVD-2026-113200 2.1

Record: EUVD-2026-113200
CVSS 4.0: 2.1 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-9283-62cg-q26h 2.1

Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in...

Record: GHSA-9283-62cg-q26h
CVSS 4.0: 2.1 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 2.6 LowCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N
Weakness: CWE-758
Updated: 2026-11-02

NVD 2.1

Record: CVE-2026-119133
CVSS 4.0: 2.1 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 2.6 LowCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N
Weakness: CWE-758
Updated: 2026-11-02

OSV 2.1

Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Misaligned VMContext via Exception Tags

Record: CVE-2026-119133
CVSS 4.0: 2.1 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Weakness: CWE-758
Updated: 2026-11-02

OSVRUSTSEC-2026-0364 2.1

Exception tags can cause host data structures to be unaligned

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-p79w-pv2r-29qp For more information see the GitHub-hosted security advisory.

Record: RUSTSEC-2026-0364
CVSS 4.0: 2.1 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-119133 2.1

Record: UBUNTU-CVE-2026-119133
CVSS 4.0: 2.1 LowCVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS 3.1: 2.6 LowCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N
Updated: 2026-11-05

Affected products

bytecodealliance wasmtime

Affected packages

Affected packages
Package	Affected	Fixed
`wasmtime` crates.io	47.0.0 up to 48.0.6, 49.0.0 up to 49.0.3	48.0.649.0.3
`rust-wasmtime` Ubuntu:24.04:LTS	All versions, plus listed versions 10.0.1+dfsg-715.0.1+dfsg-416.0.0+dfsg-216.0.0+dfsg-3	None known
`rust-wasmtime` Ubuntu:26.10	All versions, plus listed versions 36.0.5+dfsg-136.0.13+dfsg-1	None known
`rust-wasmtime` Ubuntu:26.04:LTS	All versions, plus listed versions 26.0.1+dfsg-326.0.1+dfsg-428.0.1+dfsg-329.0.1+dfsg-536.0.5+dfsg-1	None known

History

History
Recorded	Changed	Sources
Nov 5, 2026	facts	OSV
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-119133 is a low vulnerability (CVSS 2.1) in Bytecodealliance Wasmtime, published October 14, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. Fixed in wasmtime 48.0.6.

References

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