CVE-2025-66862Public exploit

c++filt crash via heap out-of-bounds read

Published Dec 29, 2025 · Updated Dec 29, 2025

Heap-based buffer overflow in GNU Binutils 2.26 c++filt allows context-dependent attackers to crash the process via crafted demangling input. The gnu_special routine in libiberty/cplus-dem.c reads one byte immediately beyond a two-byte heap allocation while recursively demangling the supplied symbol. The input must reach c++filt or another consumer of the legacy demangler; the demonstrated result is a process abort, with no confidentiality or integrity impact shown.

CVSS severity7.5
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in GNU Binutils 2.26 c++filt allows context-dependent attackers to crash the process via crafted demangling input. The gnu_special routine in libiberty/cplus-dem.c reads one byte immediately beyond a two-byte heap allocation while recursively demangling the supplied symbol. The input must reach c++filt or another consumer of the legacy demangler; the demonstrated result is a process abort, with no confidentiality or integrity impact shown.

The record

CVE
CVE-2025-66862
Published
Dec 29, 2025
Updated
Dec 29, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-122
Attack vector
local
Privileges
Unavailable

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 privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

1.8SUSECVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
3.3Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
7.5UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
2.5SUSECVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow

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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