CVE-2025-8556: CIRCL-Fourq Missing And Wrong Validation Can Vulnerability

LOW
Advisory Identifier: GHSA-2x5j-vhc8-9cwm
Share
CVSS 3.7
CWE-20 CWE-347
Published
Advisory Summary

CVE-2025-8556 is a LOW (CVSS 3.7) missing and wrong validation can vulnerability (CWE-20: Improper Input Validation) affecting CIRCL-Fourq libraries in the Go ecosystem. The issue involves missing and wrong validation can lead to incorrect results. Remediation is available by upgrading affected packages to version 1.6.1.

CVE-2025-8556 at a Glance

CVE Identifier CVE-2025-8556
GHSA Identifier GHSA-2x5j-vhc8-9cwm
Severity LOW
CVSS v3.1 Base Score 3.7
CWE Classification CWE-20: Improper Input Validation
Affected Product CIRCL-Fourq
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 3.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2025-8556

To remediate this vulnerability, upgrade all affected CIRCL-Fourq dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/cloudflare/circl fixed: 1.6.1 
Upgrade github.com/cloudflare/circl to 1.6.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/cloudflare/circl

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-8556, inspect your project dependencies for CIRCL-Fourq:

inspect dependencies for github.com/cloudflare/circl

Analyze the terminal output to locate any version of CIRCL-Fourq in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.6.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-20: Improper Input Validation, where the product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. In CIRCL-Fourq, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact The CIRCL implementation of FourQ fails to validate user-supplied low-order points during Diffie-Hellman key exchange, potentially allowing attackers to force the identity point and compromise session security. Moreover, there is an incorrect point validation in ScalarMult can lead to incorrect results in the isEqual function and if a point is on the curve. ### Patches Version 1.6.1 (https://github.com/cloudflare/circl/tree/v1.6.1) mitigates the identified issues. We acknowledge Alon Livne (Botanica Software Labs) for the reported findings.

CVE-2025-8556 Affected CIRCL-Fourq Versions

1 component(s)
Fixed Versions:
1.6.1
Product / Package Ecosystem Affected Versions Fixed Version
github.com/cloudflare/circl
golang/github.com/cloudflare/circl
Go
< 1.6.1
1.6.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/cloudflare/circl/security/advisories/GHSA-2x5j-vhc8-9cwm
NVD — CVE-2025-8556 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-8556
CIRCL-Fourq Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2025-8556
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2371624
CIRCL-Fourq Source Repository REPOSITORY
https://github.com/cloudflare/circl
CIRCL-Fourq Source Repository REPOSITORY
https://github.com/cloudflare/circl/tree/v1.6.1
news.ycombinator.com/item WEB
https://news.ycombinator.com/item?id=45669593
www.botanica.software/blog/cryptographic-... WEB
https://www.botanica.software/blog/cryptographic-issues-in-cloudflares-circl-fourq-implementation

Frequently Asked Questions

What is CVE-2025-8556?
CVE-2025-8556 is a security vulnerability in CIRCL-Fourq involving Missing and wrong validation can lead to incorrect results under CWE-20: Improper Input Validation.
Which CIRCL-Fourq versions are affected?
Affected versions include releases prior to 1.6.1 across affected packages: github.com/cloudflare/circl.
What version fixes CVE-2025-8556?
Upgrading to 1.6.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/cloudflare/circl affected?
Yes, github.com/cloudflare/circl is affected in releases prior to 1.6.1. Upgrade your dependency to 1.6.1 or later.
What is the CVSS score of CVE-2025-8556?
CVE-2025-8556 has a CVSS v3.1 base score of 3.7 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2025-8556?
CVE-2025-8556 is classified under CWE-20: Improper Input Validation (The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.).
How can I check Go dependencies for CVE-2025-8556?
Run the dependency tree command: 'inspect dependencies for github.com/cloudflare/circl'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-2x5j-vhc8-9cwm",
  "modified" : "2025-10-23T17:36:51Z",
  "published" : "2025-06-10T21:18:33Z",
  "aliases" : [ "CVE-2025-8556" ],
  "summary" : "CIRCL-Fourq: Missing and wrong validation can lead to incorrect results",
  "details" : "### Impact\nThe CIRCL implementation of FourQ fails to validate user-supplied low-order points during Diffie-Hellman key exchange, potentially allowing attackers to force the identity point and compromise session security.\n\nMoreover, there is an incorrect point validation in ScalarMult can lead to incorrect results in the isEqual function and if a point is on the curve.\n\n\n### Patches\nVersion 1.6.1 (https://github.com/cloudflare/circl/tree/v1.6.1) mitigates the identified issues.\n\nWe acknowledge Alon Livne (Botanica Software Labs) for the reported findings.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cloudflare/circl"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.6.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/cloudflare/circl/security/advisories/GHSA-2x5j-vhc8-9cwm"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-8556"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2025-8556"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2371624"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cloudflare/circl"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cloudflare/circl/tree/v1.6.1"
  }, {
    "type" : "WEB",
    "url" : "https://news.ycombinator.com/item?id=45669593"
  }, {
    "type" : "WEB",
    "url" : "https://www.botanica.software/blog/cryptographic-issues-in-cloudflares-circl-fourq-implementation"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20", "CWE-347" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-06-10T21:18:33Z",
    "nvd_published_at" : null
  }
}