CVE-2026-53433 (GCVE-0-2026-53433)

Vulnerability from cvelistv5 – Published: 2026-06-30 12:01 – Updated: 2026-06-30 13:32 X_Open Source
VLAI
Title
Denial of Service in fzf
Summary
fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n²)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single‑threaded HTTP server, blocking all other clients and resulting in denial of service. This issue was fixed in version 0.73.1.
Severity
5.7 (Medium)
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-407 - Inefficient Algorithmic Complexity
Assigner
References
Impacted products
Vendor Product Version
fzf fzf Affected: 0 , < 0.73.1 (semver)
Create a notification for this product.
Date Public
2026-06-30 12:01
Credits
Michał Majchrowicz (AFINE Team) Marcin Wyczechowski (AFINE Team)
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-53433",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-30T13:32:32.210950Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-30T13:32:52.251Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "fzf",
          "programFiles": [
            "src/server.go"
          ],
          "repo": "https://github.com/junegunn/fzf",
          "vendor": "fzf",
          "versions": [
            {
              "lessThan": "0.73.1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Micha\u0142 Majchrowicz (AFINE Team)"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Marcin Wyczechowski (AFINE Team)"
        }
      ],
      "datePublic": "2026-06-30T12:01:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen \u003cspan style=\"background-color: rgba(221, 223, 228, 0.04);\"\u003emode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n\u00b2)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.\u003c/span\u003eThis allows a single malicious request to monopolize the single\u2011threaded HTTP server, blocking all other clients and resulting in denial of service.\u003cbr\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\u003cbr\u003e\u003c/span\u003e\u003c/span\u003eThis issue was fixed in version 0.73.1.\u003cbr\u003e"
            }
          ],
          "value": "fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n\u00b2)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single\u2011threaded HTTP server, blocking all other clients and resulting in denial of service.\n\nThis issue was fixed in version 0.73.1."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "LOCAL",
            "baseScore": 5.7,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-407",
              "description": "CWE-407 Inefficient Algorithmic Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-30T12:01:14.407Z",
        "orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
        "shortName": "CERT-PL"
      },
      "references": [
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://cert.pl/en/posts/2026/06/CVE-2026-53432"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/junegunn/fzf"
        },
        {
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/junegunn/fzf/commit/7963a2c6586c0b9eaa89b8995de8f0e08cf8a4ce"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "tags": [
        "x_open-source"
      ],
      "title": "Denial of Service in fzf",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
    "assignerShortName": "CERT-PL",
    "cveId": "CVE-2026-53433",
    "datePublished": "2026-06-30T12:01:14.407Z",
    "dateReserved": "2026-06-09T11:41:37.126Z",
    "dateUpdated": "2026-06-30T13:32:52.251Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-53433",
      "date": "2026-07-04",
      "epss": "0.00215",
      "percentile": "0.11898"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-53433\",\"sourceIdentifier\":\"cvd@cert.pl\",\"published\":\"2026-06-30T13:19:13.407\",\"lastModified\":\"2026-07-02T19:01:45.227\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n\u00b2)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single\u2011threaded HTTP server, blocking all other clients and resulting in denial of service.\\n\\nThis issue was fixed in version 0.73.1.\"}],\"affected\":[{\"source\":\"cvd@cert.pl\",\"affectedData\":[{\"vendor\":\"fzf\",\"product\":\"fzf\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"src/server.go\"],\"repo\":\"https://github.com/junegunn/fzf\",\"versions\":[{\"version\":\"0\",\"lessThan\":\"0.73.1\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"cvd@cert.pl\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/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\",\"baseScore\":5.7,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"PRESENT\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"HIGH\",\"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\"}}],\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-06-30T13:32:32.210950Z\",\"id\":\"CVE-2026-53433\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"cvd@cert.pl\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-407\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:junegunn:fzf:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"0.73.1\",\"matchCriteriaId\":\"1B9C3708-1223-421E-9641-DABD4A023A81\"}]}]}],\"references\":[{\"url\":\"https://cert.pl/en/posts/2026/06/CVE-2026-53432\",\"source\":\"cvd@cert.pl\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://github.com/junegunn/fzf\",\"source\":\"cvd@cert.pl\",\"tags\":[\"Product\"]},{\"url\":\"https://github.com/junegunn/fzf/commit/7963a2c6586c0b9eaa89b8995de8f0e08cf8a4ce\",\"source\":\"cvd@cert.pl\",\"tags\":[\"Patch\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-53433\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-06-30T13:32:32.210950Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-06-30T13:32:45.588Z\"}}], \"cna\": {\"tags\": [\"x_open-source\"], \"title\": \"Denial of Service in fzf\", \"source\": {\"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Micha\\u0142 Majchrowicz (AFINE Team)\"}, {\"lang\": \"en\", \"type\": \"finder\", \"value\": \"Marcin Wyczechowski (AFINE Team)\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 5.7, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"LOCAL\", \"baseSeverity\": \"MEDIUM\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"LOW\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"NONE\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"repo\": \"https://github.com/junegunn/fzf\", \"vendor\": \"fzf\", \"product\": \"fzf\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"0.73.1\", \"versionType\": \"semver\"}], \"programFiles\": [\"src/server.go\"], \"defaultStatus\": \"unaffected\"}], \"datePublic\": \"2026-06-30T12:01:00.000Z\", \"references\": [{\"url\": \"https://cert.pl/en/posts/2026/06/CVE-2026-53432\", \"tags\": [\"third-party-advisory\"]}, {\"url\": \"https://github.com/junegunn/fzf\", \"tags\": [\"product\"]}, {\"url\": \"https://github.com/junegunn/fzf/commit/7963a2c6586c0b9eaa89b8995de8f0e08cf8a4ce\", \"tags\": [\"issue-tracking\"]}], \"x_generator\": {\"engine\": \"Vulnogram 0.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n\\u00b2)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single\\u2011threaded HTTP server, blocking all other clients and resulting in denial of service.\\n\\nThis issue was fixed in version 0.73.1.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen \u003cspan style=\\\"background-color: rgba(221, 223, 228, 0.04);\\\"\u003emode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n\\u00b2)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.\u003c/span\u003eThis allows a single malicious request to monopolize the single\\u2011threaded HTTP server, blocking all other clients and resulting in denial of service.\u003cbr\u003e\u003cspan style=\\\"background-color: rgb(255, 255, 255);\\\"\u003e\u003cspan style=\\\"background-color: rgb(255, 255, 255);\\\"\u003e\u003cbr\u003e\u003c/span\u003e\u003c/span\u003eThis issue was fixed in version 0.73.1.\u003cbr\u003e\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-407\", \"description\": \"CWE-407 Inefficient Algorithmic Complexity\"}]}], \"providerMetadata\": {\"orgId\": \"4bb8329e-dd38-46c1-aafb-9bf32bcb93c6\", \"shortName\": \"CERT-PL\", \"dateUpdated\": \"2026-06-30T12:01:14.407Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-53433\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-06-30T13:32:52.251Z\", \"dateReserved\": \"2026-06-09T11:41:37.126Z\", \"assignerOrgId\": \"4bb8329e-dd38-46c1-aafb-9bf32bcb93c6\", \"datePublished\": \"2026-06-30T12:01:14.407Z\", \"assignerShortName\": \"CERT-PL\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.