CVE-2025-66863Public exploit

Process crash via invalid discriminator read

Published Dec 29, 2025 · Updated Dec 29, 2025

A segmentation fault in GNU Binutils 2.26 c++filt allows local users to crash the process by supplying crafted demangler input. The d_discriminator parser in libiberty/cp-demangle.c performs an invalid high-address read while decoding a discriminator in the mangled name. Triggering the flaw requires passing the crafted input to c++filt or another caller of the affected demangler, and the demonstrated consequence is process termination.

CVSS severity7.5
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A segmentation fault in GNU Binutils 2.26 c++filt allows local users to crash the process by supplying crafted demangler input. The d_discriminator parser in libiberty/cp-demangle.c performs an invalid high-address read while decoding a discriminator in the mangled name. Triggering the flaw requires passing the crafted input to c++filt or another caller of the affected demangler, and the demonstrated consequence is process termination.

The record

CVE
CVE-2025-66863
Published
Dec 29, 2025
Updated
Dec 29, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, T1499
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

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.

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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
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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