CVE-2026-4751Network attack vector

Unauthenticated process crash via unchecked buffer allocation

Published Mar 24, 2026 · Updated Mar 24, 2026

NULL pointer dereference in tmate before 2.4.0 allows remote attackers to crash the terminal-sharing process through network access. Cloned tmux routines in format.c, input.c, server-client.c, and window.c continue after libevent allocation returns NULL and dereference the result. No credentials or user interaction are required, but allocation failure requires sufficient memory pressure; the bounded consequence is a process crash.

CVSS severity5.3
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in tmate before 2.4.0 allows remote attackers to crash the terminal-sharing process through network access. Cloned tmux routines in format.c, input.c, server-client.c, and window.c continue after libevent allocation returns NULL and dereference the result. No credentials or user interaction are required, but allocation failure requires sufficient memory pressure; the bounded consequence is a process crash.

The record

CVE
CVE-2026-4751
Published
Mar 24, 2026
Updated
Mar 24, 2026
Vendor
tmate
Product
tmate
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 24, 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=0 <2.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

tmate · tmateversion=0 <2.4.0

Published CVSS scores

5.3Government Technology Agency of Singapore Cyber Security GroupCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

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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