CVE-2026-2261 (GCVE-0-2026-2261)
Vulnerability from cvelistv5
Published
2026-03-09 12:10
Modified
2026-03-11 15:02
CWE
  • CWE-772 - Missing Release of Resource after Effective Lifetime
Summary
Due to a programming error, blocklistd leaks a socket descriptor for each adverse event report it receives. Once a certain number of leaked sockets is reached, blocklistd becomes unable to run the helper script: a child process is forked, but this child dereferences a null pointer and crashes before it is able to exec the helper. At this point, blocklistd still records adverse events but is unable to block new addresses or unblock addresses whose database entries have expired. Once a second, much higher number of leaked sockets is reached, blocklistd becomes unable to receive new adverse event reports. An attacker may take advantage of this by triggering a large number of adverse events from sacrificial IP addresses to effectively disable blocklistd before launching an attack. Even in the absence of attacks or probes by would-be attackers, adverse events will occur regularly in the course of normal operations, and blocklistd will gradually run out file descriptors and become ineffective. The accumulation of open sockets may have knock-on effects on other parts of the system, resulting in a general slowdown until blocklistd is restarted.
Impacted products
Vendor Product Version
FreeBSD FreeBSD Version: 15.0-RELEASE
Create a notification for this product.
Show details on NVD website


{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-2261",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-11T15:02:47.286466Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-11T15:02:53.159Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "modules": [
            "blocklistd"
          ],
          "product": "FreeBSD",
          "vendor": "FreeBSD",
          "versions": [
            {
              "lessThan": "p3",
              "status": "affected",
              "version": "15.0-RELEASE",
              "versionType": "release"
            }
          ]
        }
      ],
      "datePublic": "2026-02-10T19:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Due to a programming error, blocklistd leaks a socket descriptor for each adverse event report it receives.\n\nOnce a certain number of leaked sockets is reached, blocklistd becomes unable to run the helper script: a child process is forked, but this child dereferences a null pointer and crashes before it is able to exec the helper.  At this point, blocklistd still records adverse events but is unable to block new addresses or unblock addresses whose database entries have expired.\n\nOnce a second, much higher number of leaked sockets is reached, blocklistd becomes unable to receive new adverse event reports.\n\nAn attacker may take advantage of this by triggering a large number of adverse events from sacrificial IP addresses to effectively disable blocklistd before launching an attack.\n\nEven in the absence of attacks or probes by would-be attackers, adverse events will occur regularly in the course of normal operations, and blocklistd will gradually run out file descriptors and become ineffective.\n\nThe accumulation of open sockets may have knock-on effects on other parts of the system, resulting in a general slowdown until blocklistd is restarted."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-772",
              "description": "CWE-772: Missing Release of Resource after Effective Lifetime",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-09T12:10:08.194Z",
        "orgId": "63664ac6-956c-4cba-a5d0-f46076e16109",
        "shortName": "freebsd"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://security.freebsd.org/advisories/FreeBSD-SA-26:03.blocklistd.asc"
        }
      ],
      "title": "blocklistd(8) socket leak",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "63664ac6-956c-4cba-a5d0-f46076e16109",
    "assignerShortName": "freebsd",
    "cveId": "CVE-2026-2261",
    "datePublished": "2026-03-09T12:10:08.194Z",
    "dateReserved": "2026-02-09T17:48:49.244Z",
    "dateUpdated": "2026-03-11T15:02:53.159Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-2261\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-11T15:02:47.286466Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-11T15:02:33.155Z\"}}], \"cna\": {\"title\": \"blocklistd(8) socket leak\", \"affected\": [{\"vendor\": \"FreeBSD\", \"modules\": [\"blocklistd\"], \"product\": \"FreeBSD\", \"versions\": [{\"status\": \"affected\", \"version\": \"15.0-RELEASE\", \"lessThan\": \"p3\", \"versionType\": \"release\"}], \"defaultStatus\": \"unknown\"}], \"datePublic\": \"2026-02-10T19:00:00.000Z\", \"references\": [{\"url\": \"https://security.freebsd.org/advisories/FreeBSD-SA-26:03.blocklistd.asc\", \"tags\": [\"vendor-advisory\"]}], \"x_generator\": {\"engine\": \"cvelib 1.8.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"Due to a programming error, blocklistd leaks a socket descriptor for each adverse event report it receives.\\n\\nOnce a certain number of leaked sockets is reached, blocklistd becomes unable to run the helper script: a child process is forked, but this child dereferences a null pointer and crashes before it is able to exec the helper.  At this point, blocklistd still records adverse events but is unable to block new addresses or unblock addresses whose database entries have expired.\\n\\nOnce a second, much higher number of leaked sockets is reached, blocklistd becomes unable to receive new adverse event reports.\\n\\nAn attacker may take advantage of this by triggering a large number of adverse events from sacrificial IP addresses to effectively disable blocklistd before launching an attack.\\n\\nEven in the absence of attacks or probes by would-be attackers, adverse events will occur regularly in the course of normal operations, and blocklistd will gradually run out file descriptors and become ineffective.\\n\\nThe accumulation of open sockets may have knock-on effects on other parts of the system, resulting in a general slowdown until blocklistd is restarted.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-772\", \"description\": \"CWE-772: Missing Release of Resource after Effective Lifetime\"}]}], \"providerMetadata\": {\"orgId\": \"63664ac6-956c-4cba-a5d0-f46076e16109\", \"shortName\": \"freebsd\", \"dateUpdated\": \"2026-03-09T12:10:08.194Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-2261\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-03-11T15:02:53.159Z\", \"dateReserved\": \"2026-02-09T17:48:49.244Z\", \"assignerOrgId\": \"63664ac6-956c-4cba-a5d0-f46076e16109\", \"datePublished\": \"2026-03-09T12:10:08.194Z\", \"assignerShortName\": \"freebsd\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


Loading…

Loading…