Vulnerability-Lookup

CVE-2026-28432 (GCVE-0-2026-28432)

Vulnerability from cvelistv5 – Published: 2026-03-09 21:19 – Updated: 2026-03-10 14:45

Title

HTTP signature verification can be bypassed

Summary

Misskey is an open source, federated social media platform. All Misskey servers prior to 2026.3.1 contain a vulnerability that allows bypassing HTTP signature verification. Although this is a vulnerability related to federation, it affects all servers regardless of whether federation is enabled or disabled. This vulnerability is fixed in 2026.3.1.

Severity

7.1 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-10 14:45 UTC

CWE

CWE-347 - Improper Verification of Cryptographic Signature

Assigner

GitHub_M mitre root

References

1 reference

URL	Tags
https://github.com/misskey-dev/misskey/security/a…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version	CPE status
misskey-dev	misskey	Affected: < 2026.3.1	guessed

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-28432

Vulnerability from fkie_nvd - Published: 2026-03-10 07:43 - Updated: 2026-06-17 10:28

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/misskey-dev/misskey/security/advisories/GHSA-grwc-c762-gcvp	Vendor Advisory

Impacted products

	Vendor	Product	Version
	misskey	misskey	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "misskey",
          "vendor": "misskey-dev",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2026.3.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "versionEndExcluding": "2026.3.1",
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          "negate": false,
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    },
    {
      "lang": "es",
      "value": "Misskey es una plataforma de redes sociales de c\u00f3digo abierto y federada. Todos los servidores Misskey anteriores a 2026.3.1 contienen una vulnerabilidad que permite eludir la verificaci\u00f3n de firmas HTTP. Aunque esta es una vulnerabilidad relacionada con la federaci\u00f3n, afecta a todos los servidores independientemente de si la federaci\u00f3n est\u00e1 habilitada o deshabilitada. Esta vulnerabilidad est\u00e1 corregida en 2026.3.1."
    }
  ],
  "id": "CVE-2026-28432",
  "lastModified": "2026-06-17T10:28:38.120",
  "metrics": {
    "cvssMetricV31": [
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          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.