CVE-2026-115389
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
1.0
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
- Record
CVE-2026-115389- CVSS 4.0
- 1.0 Low
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - CVSS 3.1
- 2.3 Low
CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L - Weakness
- CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2026-108320
1.0
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
- Record
EUVD-2026-108320- CVSS 4.0
- 1.0 Low
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-3g9q-2gmg-4cvp
1.0
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately...
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
- Record
GHSA-3g9q-2gmg-4cvp- CVSS 4.0
- 1.0 Low
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/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
- 2.3 Low
CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L - Weakness
- CWE-770
- Updated
- 2026-11-02
NVD
1.0
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
- Record
CVE-2026-115389- CVSS 4.0
- 1.0 Low
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/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
- 2.3 Low
CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L - Weakness
- CWE-770
- Updated
- 2026-11-02
OSV
1.0
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
- Record
CVE-2026-115389- CVSS 4.0
- 1.0 Low
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-115389
1.0
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
- Record
DEBIAN-CVE-2026-115389- CVSS 4.0
- 1.0 Low
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/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 - Updated
- 2026-11-03
OSVRUSTSEC-2026-0316
1.0
Dynamic record lifting can allocate beyond the hostcall fuel limit
This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-jqpg-j7w6-42pr For more information see the GitHub-hosted security advisory.
- Record
RUSTSEC-2026-0316- CVSS 4.0
- 1.0 Low
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-115389
1.0
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
- Record
UBUNTU-CVE-2026-115389- CVSS 4.0
- 1.0 Low
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - CVSS 3.1
- 2.3 Low
CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
rust-wasmtimeDebian:13 |
All versions, plus listed versions 26.0.1+dfsg-1026.0.1+dfsg-326.0.1+dfsg-426.0.1+dfsg-526.0.1+dfsg-6 Show 39 moreShow less26.0.1+dfsg-726.0.1+dfsg-826.0.1+dfsg-927.0.0+dfsg-227.0.0+dfsg-327.0.0+dfsg-428.0.1+dfsg-128.0.1+dfsg-228.0.1+dfsg-329.0.1+dfsg-129.0.1+dfsg-229.0.1+dfsg-329.0.1+dfsg-429.0.1+dfsg-529.0.1+dfsg-629.0.1+dfsg-729.0.1+dfsg-836.0.11+dfsg-136.0.12+dfsg-136.0.12+dfsg-236.0.12+dfsg-336.0.13+dfsg-136.0.20+dfsg-136.0.5+dfsg-136.0.5+dfsg-236.0.5+dfsg-336.0.5+dfsg-436.0.5+dfsg-536.0.6+dfsg-136.0.6+dfsg-236.0.6+dfsg-336.0.6+dfsg-436.0.6+dfsg-536.0.6+dfsg-636.0.6+dfsg-736.0.7+dfsg-136.0.8+dfsg-136.0.9+dfsg-136.0.9+dfsg-2 |
None known |
rust-wasmtimeDebian:14 |
before 36.0.20+dfsg-1, plus listed versions 26.0.1+dfsg-1026.0.1+dfsg-326.0.1+dfsg-426.0.1+dfsg-526.0.1+dfsg-6 Show 38 moreShow less26.0.1+dfsg-726.0.1+dfsg-826.0.1+dfsg-927.0.0+dfsg-227.0.0+dfsg-327.0.0+dfsg-428.0.1+dfsg-128.0.1+dfsg-228.0.1+dfsg-329.0.1+dfsg-129.0.1+dfsg-229.0.1+dfsg-329.0.1+dfsg-429.0.1+dfsg-529.0.1+dfsg-629.0.1+dfsg-729.0.1+dfsg-836.0.11+dfsg-136.0.12+dfsg-136.0.12+dfsg-236.0.12+dfsg-336.0.13+dfsg-136.0.5+dfsg-136.0.5+dfsg-236.0.5+dfsg-336.0.5+dfsg-436.0.5+dfsg-536.0.6+dfsg-136.0.6+dfsg-236.0.6+dfsg-336.0.6+dfsg-436.0.6+dfsg-536.0.6+dfsg-636.0.6+dfsg-736.0.7+dfsg-136.0.8+dfsg-136.0.9+dfsg-136.0.9+dfsg-2 |
36.0.20+dfsg-1 |
wasmtimecrates.io |
0.0.0-0 up to 36.0.16, 37.0.0 up to 48.0.3, 49.0.0 up to 49.0.1 | 36.0.1648.0.349.0.1 |
rust-wasmtimeUbuntu: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-wasmtimeUbuntu:26.10 |
All versions, plus listed versions 36.0.5+dfsg-136.0.13+dfsg-1 |
None known |
rust-wasmtimeUbuntu: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
| Recorded | Changed | Sources |
|---|---|---|
| affected | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-115389 is a low vulnerability (CVSS 1.0) in Bytecodealliance Wasmtime, published September 24, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.15%, the 4th percentile. Fixed in rust-wasmtime 36.0.20+dfsg-1.
References
github.com/bytecodealliance/wasmtime/security/advisories/GHSA-jqpg-j7w6-42pr
vulncheck.com/advisories/wasmtime-before-36.0.16-37.0.0-before-48.0.3-and-49.0.0-before-49.0.1-denial-of-service-via-val-api
nvd.nist.gov/vuln/detail/CVE-2026-115389
github.com/advisories/GHSA-3g9q-2gmg-4cvp
github.com/CVEProject/cvelistV5/tree/main/cves/2026/115xxx/CVE-2026-115389.json
security-tracker.debian.org/tracker/CVE-2026-115389