Vulnerability-Lookup

GHSA-84CR-XJPW-Q9MC

Vulnerability from github – Published: 2026-09-07 15:33 – Updated: 2026-09-18 21:31

Details

LibreNMS before 26.8.0 contains an authentication bypass vulnerability in the REST API that allows unauthenticated attackers to access protected endpoints by sending numeric values instead of string tokens. Attackers can exploit MySQL type coercion by sending small integers like 0 through 9 to match token hashes, gaining access to API functionality including device credentials and administrative features that enable remote code execution through alert templates.

Severity

9.8 (Critical)


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

9.2 (Critical)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-86426"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-287"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-07T13:20:41Z",
    "severity": "CRITICAL"
  },
  "details": "LibreNMS before 26.8.0 contains an authentication bypass vulnerability in the REST API that allows unauthenticated attackers to access protected endpoints by sending numeric values instead of string tokens. Attackers can exploit MySQL type coercion by sending small integers like 0 through 9 to match token hashes, gaining access to API functionality including device credentials and administrative features that enable remote code execution through alert templates.",
  "id": "GHSA-84cr-xjpw-q9mc",
  "modified": "2026-09-18T21:31:49Z",
  "published": "2026-09-07T15:33:53Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86426"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/librenms-before-26.8.0-authentication-bypass-via-api-token-type-confusion"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-86426 (GCVE-0-2026-86426)

Vulnerability from cvelistv5 – Published: 2026-09-07 12:53 – Updated: 2026-09-08 13:39

Title

LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion

Summary

Severity

9.2 (Critical)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-08 13:38 UTC

CWE

CWE-287 - Improper Authentication

Assigner

VulnCheck CNA under the mitre root

CNA scorecard B 84/100 over 5271 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/librenms/librenms/security/adv…	vendor-advisory
https://www.vulncheck.com/advisories/librenms-bef…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
librenms	librenms	Affected: 0 , < 26.8.0 (semver) Unaffected: 26.8.0 (semver) cpe:2.3:a:librenms:librenms::::::::

Date Public

2026-08-23 00:00

Credits

rbs-astsec

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-86426",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-08T13:38:14.229547Z",
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          }
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    ],
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            },
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        }
      ],
      "cpeApplicability": [
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          ],
          "url": "https://www.vulncheck.com/advisories/librenms-before-26.8.0-authentication-bypass-via-api-token-type-confusion"
        }
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  "cveMetadata": {
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    "dateReserved": "2026-09-07T12:33:13.368Z",
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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.

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.

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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.

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GHSA-84CR-XJPW-Q9MC

CVE-2026-86426 (GCVE-0-2026-86426)

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