CVE-2025-66861Public exploit

cxxfilt crash via invalid demangled-name read

Published Dec 29, 2025 · Updated Dec 29, 2025

Out-of-bounds read in GNU Binutils 2.26 cxxfilt allows local users to crash the utility by processing a crafted PE file. The d_unqualified_name function in libiberty/cp-demangle.c dereferences an invalid high address while parsing malformed demangled-name input. Exploitation requires user interaction to feed the crafted file to cxxfilt, and the demonstrated consequence is termination of that process.

CVSS severity2.5
Low
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in GNU Binutils 2.26 cxxfilt allows local users to crash the utility by processing a crafted PE file. The d_unqualified_name function in libiberty/cp-demangle.c dereferences an invalid high address while parsing malformed demangled-name input. Exploitation requires user interaction to feed the crafted file to cxxfilt, and the demonstrated consequence is termination of that process.

The record

CVE
CVE-2025-66861
Published
Dec 29, 2025
Updated
Dec 29, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, 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

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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

2.5CISA-ADPCVSS:3.1/AV:L/AC:H/PR:N/UI:R/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
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

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Your stack

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