Vulnerability-Lookup

GHSA-4RM2-FQ3X-G7X7

Vulnerability from github – Published: 2026-06-01 21:30 – Updated: 2026-06-01 21:30

Details

Nanobot prior to version 0.2.1 contains a denial of service vulnerability in the Matrix channel media download handler that allows authenticated room members to exhaust process memory and bandwidth by sending media events with missing or invalid size metadata. Attackers can send multiple concurrent Matrix media events with omitted or invalid declared sizes to trigger simultaneous large media downloads that fully materialize response bodies before post-download rejection, consuming process resources until service degradation occurs.

Severity

4.3 (Medium)


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

5.3 (Medium)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-49140"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-01T21:16:47Z",
    "severity": "MODERATE"
  },
  "details": "Nanobot prior to version 0.2.1 contains a denial of service vulnerability in the Matrix channel media download handler that allows authenticated room members to exhaust process memory and bandwidth by sending media events with missing or invalid size metadata. Attackers can send multiple concurrent Matrix media events with omitted or invalid declared sizes to trigger simultaneous large media downloads that fully materialize response bodies before post-download rejection, consuming process resources until service degradation occurs.",
  "id": "GHSA-4rm2-fq3x-g7x7",
  "modified": "2026-06-01T21:30:45Z",
  "published": "2026-06-01T21:30:45Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-49140"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/nanobot/pull/4106"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/nanobot/commit/1d4000560dfff1acb83f5c5ca8ef3ab1f092bd14"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/nanobot/releases/tag/v0.2.1"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/nanobot-denial-of-service-via-matrix-media-download-handler"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-49140 (GCVE-0-2026-49140)

Vulnerability from cvelistv5 – Published: 2026-06-01 19:54 – Updated: 2026-07-28 01:49 X_Open Source

Title

Nanobot < 0.2.1 Denial of Service via Matrix Media Download Handler

Summary

Severity

5.3 (Medium)


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

4.3 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-02 12:34 UTC

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

VulnCheck mitre root

References

4 references

URL	Tags
https://github.com/HKUDS/nanobot/releases/tag/v0.2.1	release-notes
https://github.com/HKUDS/nanobot/pull/4106	issue-tracking
https://github.com/HKUDS/nanobot/commit/1d4000560…	patch
https://www.vulncheck.com/advisories/nanobot-deni…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
HKUDS	nanobot	Affected: 0 , < 0.2.1 (semver) cpe:2.3:a:nanobot:nanobot::::::python::*

Date Public

2026-05-29 00:00

Credits

Chia Min Jun Lennon

Show details on NVD website

JSON

To clipboard

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        "metrics": [
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                "id": "CVE-2026-49140",
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                  },
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                  },
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                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-02T12:34:52.411238Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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              "status": "affected",
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              "versionType": "semver"
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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.