CVE detail
CVE-2026-27017
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.
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 6.9 · diversity 5.0 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 0
- within the 30d window
- Peak daily
- 0
- highest bucket
Evidence
Source links by recency
1 source links · newest first
No excerpt available.
Exploitgithub.comFeb 20, 2026, 3:16 AM
Exploit code
Public exploit repository references
Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.
0 repository references · best confidence N/A · max 0 stars
Related records
Similar CVEs
6 related CVEs with shared weakness or product evidence
- CVE-2026-50303CVSS 5.5 · Medium
Use of a cryptographic primitive with a risky implementation in Windows Key Guard allows an authorized attacker to bypass a security feature locally.
- CVE-2026-46654CVSS 8.9 · High
Plonky3 is a toolkit for polynomial IOPs (PIOPs). Prior to versions 0.4.3 and 0.5.3, an attacker controlling prover-side observations can craft distinct transcripts that produce i…
- CVE-2026-44410CVSS 3.8 · Low
This vulnerability stems from a business logic flaw.Attackers can exploit legitimate application functions in unintended and abnormal ways, deviating from the designer's expectati…
- CVE-2026-29146CVSS 7.5 · High
Padding Oracle vulnerability in Apache Tomcat's EncryptInterceptor with default configuration. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.18, from 10.0.0-M1 th…
- CVE-2025-64647CVSS 5.9 · Medium
IBM Concert 1.0.0 through 2.2.0 uses weaker than expected cryptographic algorithms that could allow an attacker to decrypt highly sensitive information
- CVE-2025-62514CVSS 8.3 · High
Parsec is a cloud-based application for cryptographically secure file sharing. In versions on the 3.x branch prior to 3.6.0, `libparsec_crypto`, a component of the Parsec applicat…