CVE-2021-46195Public exploit

Denial of service via recursive Rust demangling

Published Jan 14, 2022 · Updated Aug 4, 2024

Uncontrolled recursion in GNU GCC 12.0 allows local users to crash a demangling process by supplying a crafted Rust symbol. The libiberty rust-demangle.c parser lets demangle_path and demangle_type recurse without a depth limit while decoding nested symbol structures. A user must cause a local tool to process deliberately corrupt symbol data; the bounded consequence is stack exhaustion and process termination.

CVSS severity5.5
Medium
EPSS probability0.78%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled recursion in GNU GCC 12.0 allows local users to crash a demangling process by supplying a crafted Rust symbol. The libiberty rust-demangle.c parser lets demangle_path and demangle_type recurse without a depth limit while decoding nested symbol structures. A user must cause a local tool to process deliberately corrupt symbol data; the bounded consequence is stack exhaustion and process termination.

The record

CVE
CVE-2021-46195
Published
Jan 14, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-674
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
3.3Red HatCVSS:3.1/AV:L/AC:L/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-674Uncontrolled Recursion

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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