# 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.

- **Severity:** Low 3.7 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Aug 2025
- **Updated:** 27 Oct 2026
- **Also known as:** CLEANSTART-2026-FE96698, CLEANSTART-2026-UC71482, DEBIAN-CVE-2025-8556, GHSA-2x5j-vhc8-9cwm, GO-2025-3754, MINI-2wh7-v592-vhcj, MINI-37q3-wwpp-w6f4, MINI-3q4f-5jww-2c6f, MINI-4m9p-qrvm-cr7m, MINI-4qg6-rrwg-79gv, MINI-4qwv-2w6r-7755, MINI-4wvv-rf5j-m7x2, MINI-535h-j2ph-wc3p, MINI-53pr-p368-4jwq, MINI-6q8q-xff7-p78p, MINI-6xv8-hr99-78fh, MINI-743f-cf79-qjxw, MINI-78hg-vw38-f47p, MINI-8j98-p4mf-v9rv, MINI-8v6p-h8c8-9m54, MINI-9j2q-w85q-82r9, MINI-cvmj-7v5h-p9cf, MINI-fgvw-hhj3-qfgr, MINI-gmqg-65vr-rf8h, MINI-h282-pc6g-x38q, MINI-hv78-fhpp-c9cg, MINI-mcw6-v7ch-x63q, MINI-q9c4-qj6w-hc8j, MINI-rhjj-6wqq-q7pr, MINI-rj34-x5xm-97p6, MINI-rp6q-c3px-84rf, MINI-rvjr-hm7m-r4m8, MINI-vmwh-h9v4-36cq, MINI-wmxh-p536-hvf4, MINI-x54x-5r5m-xp8m, MINI-x847-4qj3-xq3g, MINI-x9q2-qhc5-3g93, MINI-xj6h-6qcw-mqf5, MINI-xw66-q6fp-g8xg, ROOT-APP-GOBINARY-CVE-2025-8556, UBUNTU-CVE-2025-8556

## 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 (Improper Validation of Specified Type of Input)

## Which versions are affected by CVE-2025-8556?

3 open source packages ship an affected version, including github.com/cloudflare/circl.


| Package | Ecosystem | 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-8556 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2025-8556 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/cloudflare/circl (Go): affected all versions; fixed in 1.6.1
- github.com/cloudflare/circl (Go): affected all versions; fixed in 1.6.1
- github.com/cloudflare/circl (Go): affected all versions; fixed in 1.6.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-8556/ (Markdown: https://insights.sbomify.com/CVE-2025-8556/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-8556
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-8556
- OSV: https://osv.dev/vulnerability/CVE-2025-8556

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-8556/
Summaries are generated and may contain mistakes; the official description above is the record.