Use of a Risky Cryptographic Primitive Affecting nuclei package, versions <3.7.0-r4


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.01% (1st percentile)

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  • Snyk IDSNYK-WOLFILATEST-NUCLEI-15406147
  • published5 Mar 2026
  • disclosed20 Feb 2026

Introduced: 20 Feb 2026

CVE-2026-27017  (opens in a new tab)
CWE-1240  (opens in a new tab)

How to fix?

Upgrade Wolfi nuclei to version 3.7.0-r4 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nuclei package and not the nuclei package as distributed by Wolfi. See How to fix? for Wolfi relevant fixed versions and status.

uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still using it for the handshake. Versions 1.6.0 through 1.8.0 contain a fingerprint mismatch with Chrome when using GREASE ECH, related to cipher suite selection. When Chrome selects the preferred cipher suite in the outer ClientHello and for ECH, it does so consistently based on hardware support—for example, if it prefers AES for the outer cipher suite, it also uses AES for ECH. However, the Chrome parrot in uTLS hardcodes AES preference for outer cipher suites but selects the ECH cipher suite randomly between AES and ChaCha20. This creates a 50% chance of selecting ChaCha20 for ECH while using AES for the outer cipher suite, a combination impossible in Chrome. This issue only affects GREASE ECH; in real ECH, Chrome selects the first valid cipher suite when AES is preferred, which uTLS handles correctly. This issue has been fixed in version 1.8.1.

CVSS Base Scores

version 3.1