---
id: CVE-2021-3826
title: >-
  Heap/stack buffer overflow in the dlang_lname function in d-demangle.c in
  libiberty allows attackers to potentially cause a denial of service
  (segmentation fault and crash) via a crafted mangled symbol.
summary: >-
  Heap/stack buffer overflow in the dlang_lname function in d-demangle.c in
  libiberty allows attackers to potentially cause a denial of service
  (segmentation fault and crash) via a crafted mangled symbol.
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cwe:
  - CWE-119
  - CWE-787
vendor: gnu
product: gcc
affected:
  - gcc = 11.2
  - fedora = 35
  - fedora = 36
  - fedora = 37
published: '2022-09-01'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T10:17:48.920'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-3826'
references:
  - url: >-
      https://gcc.gnu.org/git/?p=gcc.git%3Ba=commit%3Bh=5481040197402be6dfee265bd2ff5a4c88e30505
    label: secalert@redhat.com
  - url: 'https://gcc.gnu.org/pipermail/gcc-patches/2021-September/579987'
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4MYLS3VR4OPL5ECRWOR4ZHMGXUSCJFZY/
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6AKZ2DTS3ATVN5PANNVLKLE5OP4OF25Q/
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7MTEHT3G6YKJ7F7MSGWYSI4UM3XBAYXZ/
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AXFC74WRZ2Q7F2TSUKPYNIL7ZPBWYI6L/
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H424YXGW7OKXS2NCAP35OP6Y4P4AW6VG/
    label: secalert@redhat.com
  - url: >-
      https://gcc.gnu.org/git/?p=gcc.git%3Ba=commit%3Bh=5481040197402be6dfee265bd2ff5a4c88e30505
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://gcc.gnu.org/pipermail/gcc-patches/2021-September/579987'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4MYLS3VR4OPL5ECRWOR4ZHMGXUSCJFZY/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6AKZ2DTS3ATVN5PANNVLKLE5OP4OF25Q/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7MTEHT3G6YKJ7F7MSGWYSI4UM3XBAYXZ/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AXFC74WRZ2Q7F2TSUKPYNIL7ZPBWYI6L/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H424YXGW7OKXS2NCAP35OP6Y4P4AW6VG/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.01377
epssPercentile: 0.71363
ingestedAt: '2026-10-14T10:25:41.195Z'
---

## Overview

Heap/stack buffer overflow in the dlang_lname function in d-demangle.c in libiberty allows attackers to potentially cause a denial of service (segmentation fault and crash) via a crafted mangled symbol.

## Affected

- `gcc = 11.2`
- `fedora = 35`
- `fedora = 36`
- `fedora = 37`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.