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Vulnerabilities

Vulnerability · CVE-2026-2261

Due to a programming error, blocklistd leaks a socket descriptor for each adverse event report it receives.

Published Mar 9, 2026 · catalog updated Jun 17, 2026 · Due to a programming

Check if you run it

No confirmed exploitation is on record for CVE-2026-2261. EPSS is 0.37%. Act only if a listed version of Due to a programming is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Due to a programming).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.37%
Remediation
Advisory link
Affected products
cpe freebsd/freebsd

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe freebsd/freebsd15.0

How to fix CVE-2026-2261

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-2261. EPSS is 0.37%. Act only if a listed version of Due to a programming is installed.

Which versions are affected?

Compare what you have installed with 15.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-772: Missing Release of Resource after Effective Lifetime. EPSS 0.37%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 9, 2026 · NIST NVD

    Detected

    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

  2. Jun 17, 2026 · NIST NVD

    Updated

    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

Sources

  • CVE.orgVulnerability recordCVE-2026-2261

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-2261

    30-day exploitation probability 0.4%

    first.org
  • NIST NVDVulnerability recordCVE-2026-2261

    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 point

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.