CVE-2026-3389Public exploit

Process crash via zero-capacity regex node allocation

Published Mar 1, 2026 · Updated Mar 1, 2026

NULL pointer dereference in Squirrel 3.0 through 3.2 allows local users to crash the interpreter via a crafted regular expression. sqstd_rex_compile allocates zero node capacity for an empty pattern, and sqstd_rex_newnode doubles zero to zero before writing the first AST node through the resulting null pointer. Execution requires local ability to run a Squirrel script, and the demonstrated consequence is a process crash without reported data access or modification.

CVSS severity5.5
Medium
EPSS probability0.17%
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 Squirrel 3.0 through 3.2 allows local users to crash the interpreter via a crafted regular expression. sqstd_rex_compile allocates zero node capacity for an empty pattern, and sqstd_rex_newnode doubles zero to zero before writing the first AST node through the resulting null pointer. Execution requires local ability to run a Squirrel script, and the demonstrated consequence is a process crash without reported data access or modification.

The record

CVE
CVE-2026-3389
Published
Mar 1, 2026
Updated
Mar 1, 2026
Vendor
Squirrel
Product
Squirrel
Classifications
CWE-404, CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 1, 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=3.0
  2. Affected versionversion=3.1
  3. Affected versionversion=3.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Squirrel · Squirrelversion=3.0; version=3.1; version=3.2

Published CVSS scores

3.3VulDBCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
1.7VulDBAV:L/AC:L/Au:S/C:N/I:N/A:P
1.9VulDBCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/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.

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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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-404Improper Resource Shutdown or Release
CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

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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