Vulnerability-Lookup

CVE-2026-40875 (GCVE-0-2026-40875)

Vulnerability from cvelistv5 – Published: 2026-04-21 19:19 – Updated: 2026-04-21 20:36

Title

mailcow: dockerized vulnerable to stored XSS in user login history real_rip

Summary

mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the user dashboard's "Seen successful connections" (login history) renders the client IP from login logs without HTML escaping. Because the server trusts the X-Real-IP header as the source IP for logging, an attacker can inject HTML/JS into this field. This Self-XSS can be exploited by a Login CSRF to force the victim into the attacker's account, and then read emails in a previous browser tab. Version 2026-03b fixes the vulnerability.

Severity

7 (High)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-21 19:53 UTC

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-80 - Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

Assigner

GitHub_M mitre root

References

1 reference

URL	Tags
https://github.com/mailcow/mailcow-dockerized/sec…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version	CPE status
mailcow	mailcow-dockerized	Affected: < 2026-03b	guessed

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-40875

Vulnerability from fkie_nvd - Published: 2026-04-21 20:17 - Updated: 2026-06-17 10:45

Severity

7.0 (High) - CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:H/VI:N/VA:N/SC:H/SI:H/SA:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q-q62h
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q-q62h

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "mailcow-dockerized",
          "vendor": "mailcow",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2026-03b"
            }
          ]
        }
      ],
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    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
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    }
  ],
  "id": "CVE-2026-40875",
  "lastModified": "2026-06-17T10:45:48.413",
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          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 7.0,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "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.