Vulnerability-Lookup

FKIE_CVE-2026-91939

Vulnerability from fkie_nvd - Published: 2026-09-15 21:16 - Updated: 2026-09-15 21:16

Severity

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

Summary

Cotonti 1.0.0 Comments plugin passes the ci GET parameter to unserialize() without allowed_classes restriction, allowing unauthenticated attackers to instantiate arbitrary PHP classes with attacker-controlled properties. Attackers can exploit PHP object injection through crafted serialized payloads to trigger gadget chains and achieve database manipulation or code execution.

References

	URL	Tags
	disclosure@vulncheck.com	https://github.com/Cotonti/Cotonti
	disclosure@vulncheck.com	https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/comments.setup.php
	disclosure@vulncheck.com	https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actions/DisplayAction.php
	disclosure@vulncheck.com	https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/CommentsWidget.php
	disclosure@vulncheck.com	https://github.com/Cotonti/Cotonti/issues/1888
	disclosure@vulncheck.com	https://github.com/Cotonti/Cotonti/pull/1889
	disclosure@vulncheck.com	https://www.vulncheck.com/advisories/cotonti-1.0.0-comments-plugin-php-object-injection-via-ci-parameter

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:composer/cotonti/cotonti",
          "product": "Cotonti",
          "programFiles": [
            "plugins/comments/inc/CommentsWidget.php"
          ],
          "repo": "https://github.com/Cotonti/Cotonti",
          "vendor": "Cotonti",
          "versions": [
            {
              "lessThanOrEqual": "1.0.0",
              "status": "affected",
              "version": "1.0.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "disclosure@vulncheck.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Cotonti 1.0.0 Comments plugin passes the ci GET parameter to unserialize() without allowed_classes restriction, allowing unauthenticated attackers to instantiate arbitrary PHP classes with attacker-controlled properties. Attackers can exploit PHP object injection through crafted serialized payloads to trigger gadget chains and achieve database manipulation or code execution."
    }
  ],
  "id": "CVE-2026-91939",
  "lastModified": "2026-09-15T21:16:48.957",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "disclosure@vulncheck.com",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "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",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "disclosure@vulncheck.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-15T21:16:48.957",
  "references": [
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/Cotonti/Cotonti"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/comments.setup.php"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actions/DisplayAction.php"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/CommentsWidget.php"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/Cotonti/Cotonti/issues/1888"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://github.com/Cotonti/Cotonti/pull/1889"
    },
    {
      "source": "disclosure@vulncheck.com",
      "url": "https://www.vulncheck.com/advisories/cotonti-1.0.0-comments-plugin-php-object-injection-via-ci-parameter"
    }
  ],
  "sourceIdentifier": "disclosure@vulncheck.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-502"
        }
      ],
      "source": "disclosure@vulncheck.com",
      "type": "Primary"
    }
  ]
}

CVE-2026-91939 (GCVE-0-2026-91939)

Vulnerability from cvelistv5 – Published: 2026-09-15 20:56 – Updated: 2026-09-15 20:56

Title

Cotonti 1.0.0 Comments Plugin PHP Object Injection via ci Parameter

Summary

Severity

9.3 (Critical)


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

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE

CWE-502 - Deserialization of Untrusted Data

Assigner

VulnCheck mitre root

References

7 references

URL	Tags
https://github.com/Cotonti/Cotonti/issues/1888	issue-tracking
https://github.com/Cotonti/Cotonti/pull/1889	patchissue-tracking
https://github.com/Cotonti/Cotonti/blob/1.0.0/plu…	technical-description
https://github.com/Cotonti/Cotonti/blob/1.0.0/plu…	technical-description
https://github.com/Cotonti/Cotonti/blob/1.0.0/plu…	technical-description
https://github.com/Cotonti/Cotonti	product
https://www.vulncheck.com/advisories/cotonti-1.0.…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
Cotonti	Cotonti	Affected: 1.0.0 , ≤ 1.0.0 (custom) cpe:2.3:a:cotonti:cotonti_siena::::::::

Date Public

2026-09-13 00:00

Credits

Harsh Raj Singhania

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:composer/cotonti/cotonti",
          "product": "Cotonti",
          "programFiles": [
            "plugins/comments/inc/CommentsWidget.php"
          ],
          "repo": "https://github.com/Cotonti/Cotonti",
          "vendor": "Cotonti",
          "versions": [
            {
              "lessThanOrEqual": "1.0.0",
              "status": "affected",
              "version": "1.0.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:cotonti:cotonti_siena:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "1.0.0",
                  "versionStartIncluding": "1.0.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "Harsh Raj Singhania"
        }
      ],
      "datePublic": "2026-09-13T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Cotonti 1.0.0 Comments plugin passes the ci GET parameter to unserialize() without allowed_classes restriction, allowing unauthenticated attackers to instantiate arbitrary PHP classes with attacker-controlled properties. Attackers can exploit PHP object injection through crafted serialized payloads to trigger gadget chains and achieve database manipulation or code execution."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-502",
              "description": "Deserialization of Untrusted Data",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-15T20:56:45.058Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Issue #1888",
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/Cotonti/Cotonti/issues/1888"
        },
        {
          "name": "Proposed fix PR #1889 (unmerged)",
          "tags": [
            "patch",
            "issue-tracking"
          ],
          "url": "https://github.com/Cotonti/Cotonti/pull/1889"
        },
        {
          "name": "CommentsWidget::run() at 1.0.0",
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/CommentsWidget.php"
        },
        {
          "name": "AJAX display controller at 1.0.0",
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actions/DisplayAction.php"
        },
        {
          "name": "Default comments permissions at 1.0.0",
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/comments.setup.php"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/Cotonti/Cotonti"
        },
        {
          "name": "VulnCheck Advisory: Cotonti 1.0.0 Comments Plugin PHP Object Injection via ci Parameter",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/cotonti-1.0.0-comments-plugin-php-object-injection-via-ci-parameter"
        }
      ],
      "title": "Cotonti 1.0.0 Comments Plugin PHP Object Injection via ci Parameter",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-91939",
    "datePublished": "2026-09-15T20:56:45.058Z",
    "dateReserved": "2026-09-15T11:07:01.912Z",
    "dateUpdated": "2026-09-15T20:56:45.058Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.