Deno is a JavaScript, TypeScript, and WebAssembly runtime. Versions 1.46.0 through 2.1.6 have an issue that affects AES-256-GCM and AES-128-GCM in Deno in which the authentication tag is not being validated. This means tampered ciphertexts or incorrect keys might not be detected, which breaks the guarantees expected from AES-GCM. Older versions of Deno correctly threw errors in such cases, as does Node.js. Without authentication tag verification, AES-GCM degrades to essentially CTR mode, removing integrity protection. Authenticated data set with set_aad is also affected, as it is incorporated into the GCM hash (ghash) but this too is not validated, rendering AAD checks ineffective. Version 2.1.7 includes a patch that addresses this issue.
https://github.com/denoland/deno/security/advisories/GHSA-2x3r-hwv5-p32x
https://github.com/denoland/deno/commit/a4003a5292bd0affefad3ecb24a8732886900f67
https://github.com/denoland/deno/commit/4f27d7cdc02e3edfb9d36275341fb8185d6e99ed
Published: 2025-06-03
Updated: 2025-06-04
Base Score: 6.4
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Severity: High
Base Score: 8.7
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00049