CVE-2025-8556 Github.com/cloudflare/circl: circl-fourq: missing and wrong validation can lead to incorrect results
Attackers can compromise session security in Diffie-Hellman key exchanges by injecting low-order points due to missing validation in the FourQ elliptic curve implementation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-8556?
CVE-2025-8556 is a low-severity vulnerability in Builds for Red Hat OpenShift, published on 6 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A flaw was found in CIRCL's implementation of the FourQ elliptic curve. This vulnerability allows an attacker to compromise session security via low-order point injection and incorrect point validation during Diffie-Hellman key exchange.
Weakness: CWE-1287
Which versions are affected by CVE-2025-8556?
3 open source packages ship an affected version, including github.com/cloudflare/circl.
| Package | Affected | Fixed in |
|---|---|---|
github.com/cloudflare/circl Go | All versions | 1.6.1 |
github.com/cloudflare/circl Go | All versions | 1.6.1 |
github.com/cloudflare/circl Go | All versions | 1.6.1 |
How do I fix CVE-2025-8556?
Upgrade github.com/cloudflare/circl to 1.6.1 or later.
Is CVE-2025-8556 being exploited?
There is no known exploitation of CVE-2025-8556 in the wild and no public exploit code.
Sources
Also known as CLEANSTART-2026-FE96698, CLEANSTART-2026-UC71482, DEBIAN-CVE-2025-8556, GHSA-2x5j-vhc8-9cwm, GO-2025-3754, MINI-2wh7-v592-vhcj and 35 more.