CVE-2025-66864Public exploit

cxxfilt crash via null-pointer read

Published Dec 29, 2025 · Updated Dec 29, 2025

NULL-pointer dereference in cxxfilt in GNU Binutils 2.26 allows local users to crash the process with crafted demangling input. In d_print_comp_inner in libiberty/cp-demangle.c, a read through a null pointer at line 4442 raises a segmentation fault while cxxfilt renders the malformed symbol. An attacker must cause a user or local workflow to pass the crafted input to cxxfilt; the demonstrated consequence is termination of that process.

CVSS severity5.5
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

NULL-pointer dereference in cxxfilt in GNU Binutils 2.26 allows local users to crash the process with crafted demangling input. In d_print_comp_inner in libiberty/cp-demangle.c, a read through a null pointer at line 4442 raises a segmentation fault while cxxfilt renders the malformed symbol. An attacker must cause a user or local workflow to pass the crafted input to cxxfilt; the demonstrated consequence is termination of that process.

The record

CVE
CVE-2025-66864
Published
Dec 29, 2025
Updated
Dec 29, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 29, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
7.5NVDCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499.004Application or System Exploitation

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo