What’s Vulnerable › Vulnerabilities

CVE-2021-43790: Use After Free in lucet

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-11-30 · updated 2026-06-17
• Weakness: CWE-416

Description

Lucet is a native WebAssembly compiler and runtime. There is a bug in the main branch of `lucet-runtime` affecting all versions published to crates.io that allows a use-after-free in an Instance object that could result in memory corruption, data race, or other related issues. This bug was introduced early in the development of Lucet and is present in all releases. As a result of this bug, and dependent on the memory backing for the Instance objects, it is possible to trigger a use-after-free when the Instance is dropped. Users should upgrade to the main branch of the Lucet repository. Lucet no longer provides versioned releases on crates.io. There is no way to remediate this vulnerability without upgrading.

Affected products

• bytecodealliance lucet: through 0.6.1

References

• https://crates.io/crates/lucet-runtime
• https://github.com/bytecodealliance/lucet/commit/7c7757c772fb709c61b1442bcc1e1fbee97bf4a8
• https://github.com/bytecodealliance/lucet/security/advisories/GHSA-hf79-8hjp-rrvq
• https://crates.io/crates/lucet-runtime
• https://github.com/bytecodealliance/lucet/commit/7c7757c772fb709c61b1442bcc1e1fbee97bf4a8
• https://github.com/bytecodealliance/lucet/security/advisories/GHSA-hf79-8hjp-rrvq

Get alerted when CVE-2021-43790 or the next vulnerability affects your stack