Vulnerability-Lookup

CVE-2026-45056 (GCVE-0-2026-45056)

Vulnerability from cvelistv5 – Published: 2026-09-11 21:13 – Updated: 2026-09-11 21:13

Title

Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution

Summary

matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the `sender_device_keys` property. This could be exploited to forge an encrypted to-device event, but only if the attacker colludes with the homeserver operator. This issue is fixed in matrix-sdk-crypto 0.17.0. There are no known workarounds for the issue.

Severity

6.9 (Medium)


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

CWE

CWE-290 - Authentication Bypass by Spoofing

Assigner

GitHub_M mitre root

References

4 references

URL	Tags
https://github.com/matrix-org/matrix-rust-sdk/sec…	x_refsource_CONFIRM
https://github.com/matrix-org/matrix-rust-sdk/pull/6553	x_refsource_MISC
https://github.com/matrix-org/matrix-rust-sdk/rel…	x_refsource_MISC
https://rustsec.org/advisories/RUSTSEC-2026-0159.html	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
matrix-org	matrix-rust-sdk	Affected: >= 0.12.0, < 0.16.1	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "matrix-rust-sdk",
          "vendor": "matrix-org",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.12.0, \u003c 0.16.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the `sender_device_keys` property. This could be exploited to forge an encrypted to-device event, but only if the attacker colludes with the homeserver operator. This issue is fixed in matrix-sdk-crypto 0.17.0. There are no known workarounds for the issue."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "HIGH",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-290",
              "description": "CWE-290: Authentication Bypass by Spoofing",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-11T21:13:56.332Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42"
        },
        {
          "name": "https://github.com/matrix-org/matrix-rust-sdk/pull/6553",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/matrix-org/matrix-rust-sdk/pull/6553"
        },
        {
          "name": "https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1"
        },
        {
          "name": "https://rustsec.org/advisories/RUSTSEC-2026-0159.html",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://rustsec.org/advisories/RUSTSEC-2026-0159.html"
        }
      ],
      "source": {
        "advisory": "GHSA-wfq4-36m3-9g42",
        "discovery": "UNKNOWN"
      },
      "title": "Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45056",
    "datePublished": "2026-09-11T21:13:56.332Z",
    "dateReserved": "2026-05-08T18:07:27.342Z",
    "dateUpdated": "2026-09-11T21:13:56.332Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-45056",
      "date": "2026-06-14",
      "epss": "0.0005",
      "percentile": "0.16153"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-45056\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-09-11T22:16:37.263\",\"lastModified\":\"2026-09-11T22:16:37.263\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the `sender_device_keys` property. This could be exploited to forge an encrypted to-device event, but only if the attacker colludes with the homeserver operator. This issue is fixed in matrix-sdk-crypto 0.17.0. There are no known workarounds for the issue.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"matrix-org\",\"product\":\"matrix-rust-sdk\",\"versions\":[{\"version\":\"\u003e= 0.12.0, \u003c 0.16.1\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/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\",\"baseScore\":6.9,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"HIGH\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"NONE\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-290\"}]}],\"references\":[{\"url\":\"https://github.com/matrix-org/matrix-rust-sdk/pull/6553\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://rustsec.org/advisories/RUSTSEC-2026-0159.html\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}

FKIE_CVE-2026-45056

Vulnerability from fkie_nvd - Published: 2026-09-11 22:16 - Updated: 2026-09-11 22:16

Severity

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

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/matrix-org/matrix-rust-sdk/pull/6553
	security-advisories@github.com	https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1
	security-advisories@github.com	https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42
	security-advisories@github.com	https://rustsec.org/advisories/RUSTSEC-2026-0159.html

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "matrix-rust-sdk",
          "vendor": "matrix-org",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.12.0, \u003c 0.16.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the `sender_device_keys` property. This could be exploited to forge an encrypted to-device event, but only if the attacker colludes with the homeserver operator. This issue is fixed in matrix-sdk-crypto 0.17.0. There are no known workarounds for the issue."
    }
  ],
  "id": "CVE-2026-45056",
  "lastModified": "2026-09-11T22:16:37.263",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.9,
          "baseSeverity": "MEDIUM",
          "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": "HIGH",
          "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:H/UI:N/VC:N/VI:H/VA:N/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": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-11T22:16:37.263",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/pull/6553"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0159.html"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-290"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

GHSA-WFQ4-36M3-9G42

Vulnerability from github – Published: 2026-06-04 14:47 – Updated: 2026-06-04 14:47

Summary

Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution

Details

Impact

The matrix-sdk-crypto crate before 0.16.1 is missing a check for the sender's user ID when decrypting an Olm-encrypted to-device message containing the sender_device_keys property.

This could be exploited to spoof the sender of an encrypted to-device message, but only if the attacker colludes with (or is) the homeserver operator.

Patches

This issue is fixed in matrix-sdk-crypto 0.16.1.

Workarounds

There are no known workarounds for the issue.

References

This issue was fixed in https://github.com/matrix-org/matrix-rust-sdk/pull/6553.

For more information

If you have any questions or comments about this advisory, please email us at security at matrix.org.

Severity

6.9 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "matrix-sdk-crypto"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.12.0"
            },
            {
              "fixed": "0.16.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45056"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-290"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-04T14:47:05Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nThe `matrix-sdk-crypto` crate before 0.16.1 is missing a check for the sender\u0027s user ID when decrypting an Olm-encrypted to-device message containing the `sender_device_keys` property.\n\nThis could be exploited to spoof the sender of an encrypted to-device message, but only if the attacker colludes with (or is) the homeserver operator.\n\n### Patches\n\nThis issue is fixed in `matrix-sdk-crypto` 0.16.1.\n\n### Workarounds\n\nThere are no known workarounds for the issue.\n\n### References\n\nThis issue was fixed in https://github.com/matrix-org/matrix-rust-sdk/pull/6553.\n\n### For more information\n\nIf you have any questions or comments about this advisory, please email us at [security at matrix.org](mailto:security@matrix.org).",
  "id": "GHSA-wfq4-36m3-9g42",
  "modified": "2026-06-04T14:47:05Z",
  "published": "2026-06-04T14:47:05Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/pull/6553"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/matrix-org/matrix-rust-sdk"
    },
    {
      "type": "WEB",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1"
    },
    {
      "type": "WEB",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0159.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution"
}

rustsec-2026-0159

Vulnerability from osv_rustsec

Published

2026-06-03 12:00

Modified

2026-06-04 12:02

Summary

Sender-binding gaps in to-device messages

Details

The matrix-sdk-crypto crate before 0.16.1 is missing a check for the sender's user ID when decrypting an Olm-encrypted to-device message containing the sender_device_keys property.

This could be exploited to spoof the sender of an encrypted to-device message, but only if the attacker colludes with (or is) the homeserver operator.

References

URL

Type

	https://crates.io/crates/matrix-sdk-crypto	PACKAGE
	https://rustsec.org/advisories/RUSTSEC-2026-0159.html	ADVISORY
	https://github.com/matrix-org/matrix-rust-sdk/sec…	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "categories": [],
        "cvss": null,
        "informational": null
      },
      "ecosystem_specific": {
        "affected_functions": null,
        "affects": {
          "arch": [],
          "functions": [],
          "os": []
        }
      },
      "package": {
        "ecosystem": "crates.io",
        "name": "matrix-sdk-crypto",
        "purl": "pkg:cargo/matrix-sdk-crypto"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.12.0"
            },
            {
              "fixed": "0.16.1"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "versions": []
    }
  ],
  "aliases": [
    "CVE-2026-45056",
    "GHSA-wfq4-36m3-9g42"
  ],
  "database_specific": {
    "license": "CC0-1.0"
  },
  "details": "The matrix-sdk-crypto crate before 0.16.1 is missing a check for the sender\u0027s\nuser ID when decrypting an Olm-encrypted to-device message containing the\nsender_device_keys property.\n\nThis could be exploited to spoof the sender of an encrypted to-device message,\nbut only if the attacker colludes with (or is) the homeserver operator.",
  "id": "RUSTSEC-2026-0159",
  "modified": "2026-06-04T12:02:36Z",
  "published": "2026-06-03T12:00:00Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://crates.io/crates/matrix-sdk-crypto"
    },
    {
      "type": "ADVISORY",
      "url": "https://rustsec.org/advisories/RUSTSEC-2026-0159.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42"
    }
  ],
  "related": [],
  "severity": [],
  "summary": "Sender-binding gaps in to-device messages"
}

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.

Action not permitted

CVE-2026-45056 (GCVE-0-2026-45056)

FKIE_CVE-2026-45056

GHSA-WFQ4-36M3-9G42

Impact

Patches

Workarounds

References

For more information

rustsec-2026-0159

Vulnerability from osv_rustsec

Tags

Sightings

Nomenclature