On some platforms, when an attacker can time decapsulation of Kyber on forged cipher texts, they could possibly learn (parts of) the secret key.
Full advisory text at GitHub advisory.
go package report
Is github.com/cloudflare/circl safe?
github.com/cloudflare/circl (go) has 4 known vulnerabilities, the worst rated HIGH. Upgrade to 1.6.3 or later to clear all of them. No malicious-package signal is recorded.
// reach
3 direct dependencies
2 carry known advisories, worst CRITICAL
636 packages depend on it
an advisory here reaches each of them
Create a free accountfor every dependency path, dependent and what to upgrade
// ai model usage
Tracked for PyPI packages. HuggingFace models declare Python dependencies, so go packages are not covered.
cvss
7.5
high
severity band, no base score published
epss
not scored
chance of exploitation in 30 days
xyz score
4.0
medium
CyberXYZ composite out of 10
fig. 01 — GHSA-9763-4f94-gfch, the advisory selected below
// 4 advisories
Is github.com/cloudflare/circl safe to install?
CyberXYZ does not call a package safe in absolute terms. It records 4 known vulnerabilities for github.com/cloudflare/circl (go), the worst rated HIGH, and no malicious-package signal. Whether it is acceptable depends on the version you run.
Does github.com/cloudflare/circl have known vulnerabilities?
Yes. CyberXYZ records 4 known vulnerabilities for github.com/cloudflare/circl (go), the worst rated HIGH. They are GHSA-9763-4f94-gfch, GHSA-2q89-485c-9j2x, GHSA-q9hv-hpm4-hj6x, GHSA-2x5j-vhc8-9cwm.
Which version of github.com/cloudflare/circl should I use?
1.6.3 or later clears every advisory recorded for github.com/cloudflare/circl (go). Check the release you pick before installing it.
How do I check github.com/cloudflare/circl before installing?
Search github.com/cloudflare/circl in CyberXYZ Check at https://cyberxyz.io/check?q=github.com%2Fcloudflare%2Fcircl. The xyz Scanner checks a project's dependencies, and CyberXYZ Proxy checks each package as it is installed.
Checked 2026-11-15 at 10:08 UTC. The most recent advisory here was published 2026-02-25. Updated continuously from NVD, GHSA, OSV and CNA feeds.