CVE-2026-42505
MEDIUMCVSS 5.3/10EPSS 0.42%
Last modified
CVE-2026-42505 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.. EPSS estimates a 0.42% chance of exploitation in the next 30 days.
Description
Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions | Update |
|---|---|---|---|
| Golang | Go | < 1.25.12 | — |
| Golang | Go | >= 1.26.0, < 1.26.5 | — |
| Golang | Go | 1.27 | Rc1 |
References
- https://go.dev/issue/79282Issue Tracking, Patch
- https://groups.google.com/g/golang-announce/c/OrmQE_Yp5ScMailing List, Release Notes, Vendor Advisory
- https://pkg.go.dev/vuln/GO-2026-5856Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-42505?
Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.
How severe is CVE-2026-42505?
CVE-2026-42505 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.42% probability of exploitation in the next 30 days.
How do I fix CVE-2026-42505?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2026-42505?
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Scan your code nowSource: NVD / NIST