CVE-2026-2261Network attack vector

Service disablement via per-report socket descriptor leak

Published Mar 9, 2026 · Updated Mar 9, 2026

Resource exhaustion in blocklistd in The FreeBSD Project FreeBSD 15.0-RELEASE through p2 allows remote attackers to disable IP blocking. The process() function leaves bi_fd open after every adverse event report instead of closing the received descriptor on all exits. A large pool of sacrificial IP addresses accelerates exhaustion until blocklistd cannot run its helper or accept reports, while routine events eventually cause the same failure.

CVSS severity7.5
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in blocklistd in The FreeBSD Project FreeBSD 15.0-RELEASE through p2 allows remote attackers to disable IP blocking. The process() function leaves bi_fd open after every adverse event report instead of closing the received descriptor on all exits. A large pool of sacrificial IP addresses accelerates exhaustion until blocklistd cannot run its helper or accept reports, while routine events eventually cause the same failure.

The record

CVE
CVE-2026-2261
Published
Mar 9, 2026
Updated
Mar 9, 2026
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
CWE-772, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=15.0-RELEASE <p3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The FreeBSD Project · FreeBSDversion=15.0-RELEASE <p3

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-772Missing Release of Resource after Effective Lifetime
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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