RUSTSEC-2026-0315 `call_ref` and exception `catch` can drop some fuel accounting, leading to exponential fuel amplification

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-m63x-6p34-q65x For more information see the GitHub-hosted security advisory...

RUSTSEC-2026-0313 Outgoing HTTP body write allows guest-driven host memory exhaustion

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-c9gc-w9vx-w86p For more information see the GitHub-hosted security advisory...

RUSTSEC-2026-0316 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...

Outgoing HTTP body write allows guest-driven host memory exhaustion

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-c9gc-w9vx-w86p For more information see the GitHub-hosted security advisory...

RUSTSEC-2026-0314 Guest can panic host through filesystem datetime overflow

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-j2g9-4prp-pf6h For more information see the GitHub-hosted security advisory...

Guest can panic host through filesystem datetime overflow

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-j2g9-4prp-pf6h For more information see the GitHub-hosted security advisory...

`call_ref` and exception `catch` can drop some fuel accounting, leading to exponential fuel amplification

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-m63x-6p34-q65x For more information see the GitHub-hosted security advisory...

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...

CLEANSTART-2026-SI85644 Security fix for ghsa-cq8v-f236-94qc applied in: wasmtime 40.0.0-r0, ztunnel-fips 1.27.8-r3, ztunnel-fips 1.28.5-r1, ztunnel-fips 1.28.7-r0, ztunnel-fips 1.29.1-r1, ztunnel-fips 1.30.0-r0

ghsa-cq8v-f236-94qc affects multiple packages. This issue is resolved in later releases. See references for individual vulnerability details...

CLEANSTART-2026-OG35217 Security fix for CVE-2026-25541 applied in: wasmtime 40.0.0-r0, ztunnel-fips 1.27.8-r4

CVE-2026-25541 affects multiple packages. This issue is resolved in later releases. See references for individual vulnerability details...

wasmtime:wast_tests: Stack-use-after-scope in wast_tests

Project: https://github.com/bytecodealliance/wasmtime.git Detailed Report: https://oss-fuzz.com/testcase?key=6483688326758400 Project: wasmtime Fuzzing Engine: libFuzzer Fuzz Target: wasttests Job Type: libfuzzerasanwasmtime Platform Id: linux Crash Type: Stack-use-after-scope WRITE 7 Crash...

Wasmtime has a leak in WASIp1 `fd_renumber` implementation

Impact Wasmtime's native implementation of WASIp1 suffers from a leak in the fdrenumber function where the file descriptor being renumbered to is not properly closed. Wasmtime's implementation erroneously only updated the table of descriptors for WASIp1 and didn't update the underlying table of...

EUVD-2026-41136

Wasmtime has a leak in WASIp1 fdrenumber implementation...

GHSA-3P27-QVP9-27QF Wasmtime has a leak in WASIp1 `fd_renumber` implementation

Impact Wasmtime's native implementation of WASIp1 suffers from a leak in the fdrenumber function where the file descriptor being renumbered to is not properly closed. Wasmtime's implementation erroneously only updated the table of descriptors for WASIp1 and didn't update the underlying table of...

JLSEC-2026-1364 Wasmtime has out-of-bounds write or crash when transcoding component model strings

Impact Wasmtime's implementation of transcoding strings between components contains a bug where the return value of a guest component's realloc is not validated before the host attempts to write through the pointer. This enables a guest to cause the host to write arbitrary transcoded string bytes...

JLSEC-2026-1354 Wasmtime: Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding

Summary Wasmtime contains a vulnerability where when transcoding a UTF-16 string to the latin1+utf16 component-model encoding it would incorrectly validate the byte length of the input string when performing a bounds check. Specifically the number of code units were checked instead of the byte...

JLSEC-2026-1358 Wasmtime has host data leakage with 64-bit tables and Winch

Impact Wasmtime's Winch compiler contains a bug where a 64-bit table, part of the memory64 proposal of WebAssembly, incorrectly translated the table.size instruction. This bug could lead to disclosing data on the host's stack to WebAssembly guests. The host's stack can possibly contain sensitive...

JLSEC-2026-1367

Wasmtime is a runtime for WebAssembly. All versions prior to 24.0.10; versions 25.0.0 through those before 36.0.11; versions 37.0.0 through those before 44.0.3; and versions 45.0.0 and 45.0.1 contain a native implementation of WASIp1 which suffers from a leak in the fdrenumber function where the...

JLSEC-2026-1368

Wasmtime is a runtime for WebAssembly. Prior to 24.0.11, 36.0.12, 45.0.3, and 46.0.1, wasmtime-wasi hard-link creation and renaming check directory permissions but not matching FilePerms on source and destination preopens, allowing a WASI guest with a read-only source file capability to overwrite...

JLSEC-2026-1365 wasmtime has a panic when allocating a table exceeding the size of the host's address space

Impact Wasmtime's allocation logic for a WebAssembly table contained checked arithmetic which panicked on overflow. This overflow is possible to trigger, and thus panic, when a table with an extremely large size is allocated. This is possible with the WebAssembly memory64 proposal where tables ca...