CVE-2026-42505

MEDIUM
Published Jul 8, 2026 Modified Jul 13, 2026 CWE-201

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.

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CVSS v3.1 Score

5.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0041
Probability of exploitation
0.34%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-201 CWE-201

Affected Products

Vendor Product
golang go
golang go
golang go

References

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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).
How severe is CVE-2026-42505? +
CVE-2026-42505 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0041, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-42505? +
CVE-2026-42505 affects products from golang, specifically: go. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-42505? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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