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SCA: security update for github.com/refraction-networking/utls (GHSA-pmc3-p9hx-jq96)

medium Tenable Cloud Security Plugin ID 437859

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - uTLS is a fork of crypto/tls, created to customize ClientHello for fingerprinting resistance while still
 using it for the handshake. In versions 1.6.7 and below, uTLS did not implement the TLS 1.3 downgrade
 protection mechanism specified in RFC 8446 Section 4.1.3 when using a uTLS ClientHello spec. This allowed
 an active network adversary to downgrade TLS 1.3 connections initiated by a uTLS client to a lower TLS
 version (e.g., TLS 1.2) by modifying the ClientHello message to exclude the SupportedVersions extension,
 causing the server to respond with a TLS 1.2 ServerHello (along with a downgrade canary in the ServerHello
 random field). Because uTLS did not check the downgrade canary in the ServerHello random field, clients
 would accept the downgraded connection without detecting the attack. This attack could also be used by an
 active network attacker to fingerprint uTLS connections. This issue has been fixed in version 1.7.0.
 (CVE-2026-26994)

See Also

https://github.com/advisories/GHSA-pmc3-p9hx-jq96

Plugin Details

Severity: Medium

ID: 437859

Version: Revision 1.9

Type: Local

Family: SCA Checks

Published: 2/19/2026

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 2.1

Percentile: 7.45

Vendor

Vendor Severity: Medium

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 4.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

CVSS Score Source: CVE-2026-26994

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 4/23/2025

Vulnerability Publication Date: 4/23/2025

Reference Information

CVE: CVE-2026-26994

cwe: CWE-693