Vulnerability-Lookup

GHSA-8W6R-CPH7-4J6V

Vulnerability from github – Published: 2026-09-08 18:31 – Updated: 2026-09-08 18:31

Details

OpenBSD before commit 1ee99df contains an inverted comparison vulnerability in the ieee80211_michael_mic_failure() function within sys/net80211/ieee80211_crypto_tkip.c that allows unauthenticated attackers within RF range to trigger denial of service by sending two malformed TKIP frames separated by more than 60 seconds. Attackers can exploit the reversed TKIP MIC failure countermeasure window check to deauthenticate all associated TKIP stations and block reassociation for up to 90 seconds, while within-window MIC failures that should engage countermeasures are silently discarded, leaving key-recovery attempts undetected.

Severity

5.3 (Medium)


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

6.0 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-56101"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-697"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-08T16:18:09Z",
    "severity": "MODERATE"
  },
  "details": "OpenBSD before commit 1ee99df contains an inverted comparison vulnerability in the ieee80211_michael_mic_failure() function within sys/net80211/ieee80211_crypto_tkip.c that allows unauthenticated attackers within RF range to trigger denial of service by sending two malformed TKIP frames separated by more than 60 seconds. Attackers can exploit the reversed TKIP MIC failure countermeasure window check to deauthenticate all associated TKIP stations and block reassociation for up to 90 seconds, while within-window MIC failures that should engage countermeasures are silently discarded, leaving key-recovery attempts undetected.",
  "id": "GHSA-8w6r-cph7-4j6v",
  "modified": "2026-09-08T18:31:50Z",
  "published": "2026-09-08T18:31:50Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56101"
    },
    {
      "type": "WEB",
      "url": "https://github.com/openbsd/src/commit/1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5a"
    },
    {
      "type": "WEB",
      "url": "https://pop.argus-systems.ai/advisory/adv-209.html"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/openbsd-ieee80211-crypto-tkip-c-tkip-mic-countermeasure-logic-inversion-dos"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/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-2026-56101 (GCVE-0-2026-56101)

Vulnerability from cvelistv5 – Published: 2026-09-08 16:00 – Updated: 2026-09-10 15:02 X_Open Source

Title

OpenBSD ieee80211_crypto_tkip.c TKIP MIC Countermeasure Logic Inversion DoS

Summary

Severity

6 (Medium)


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

5.3 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-10 13:49 UTC

CWE

CWE-697 - Incorrect Comparison

Assigner

VulnCheck mitre root

References

3 references

URL	Tags
https://pop.argus-systems.ai/advisory/adv-209.html	technical-descriptionexploit
https://github.com/openbsd/src/commit/1ee99dfcc4d…	patch
https://www.vulncheck.com/advisories/openbsd-ieee…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
OpenBSD	OpenBSD	Affected: 0 , < 1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5a (git)

Date Public

2026-07-15 00:00

Credits

Argus Systems

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-56101",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-10T13:49:14.964977Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-10T15:02:16.176Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:github/openbsd/src",
          "product": "OpenBSD",
          "repo": "https://github.com/openbsd/src",
          "vendor": "OpenBSD",
          "versions": [
            {
              "lessThan": "1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5a",
              "status": "affected",
              "version": "0",
              "versionType": "git"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Argus Systems"
        }
      ],
      "datePublic": "2026-07-15T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "OpenBSD before commit 1ee99df contains an inverted comparison vulnerability in the ieee80211_michael_mic_failure() function within sys/net80211/ieee80211_crypto_tkip.c that allows unauthenticated attackers within RF range to trigger denial of service by sending two malformed TKIP frames separated by more than 60 seconds. Attackers can exploit the reversed TKIP MIC failure countermeasure window check to deauthenticate all associated TKIP stations and block reassociation for up to 90 seconds, while within-window MIC failures that should engage countermeasures are silently discarded, leaving key-recovery attempts undetected."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "ADJACENT",
            "baseScore": 6,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
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            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
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          ]
        },
        {
          "cvssV3_1": {
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            "attackVector": "ADJACENT_NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
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          ]
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      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-697",
              "description": "Incorrect Comparison",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-08T16:00:30.572Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
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      },
      "references": [
        {
          "name": "Argus Systems Advisory",
          "tags": [
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          ],
          "url": "https://pop.argus-systems.ai/advisory/adv-209.html"
        },
        {
          "name": "Patch Commit",
          "tags": [
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          "url": "https://github.com/openbsd/src/commit/1ee99dfcc4ddc87afc6395d5d3094e9d2314fb5a"
        },
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/openbsd-ieee80211-crypto-tkip-c-tkip-mic-countermeasure-logic-inversion-dos"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "tags": [
        "x_open-source"
      ],
      "title": "OpenBSD ieee80211_crypto_tkip.c TKIP MIC Countermeasure Logic Inversion DoS",
      "x_generator": {
        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-56101",
    "datePublished": "2026-09-08T16:00:30.572Z",
    "dateReserved": "2026-06-18T19:15:10.649Z",
    "dateUpdated": "2026-09-10T15:02:16.176Z",
    "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.

Action not permitted

GHSA-8W6R-CPH7-4J6V

CVE-2026-56101 (GCVE-0-2026-56101)

Tags

Sightings

Nomenclature