---
id: CVE-2021-36087
title: >-
  The CIL compiler in SELinux 3.2 has a heap-based buffer over-read in
  ebitmap_match_any (called indirectly from cil_check_neverallow)
summary: >-
  The CIL compiler in SELinux 3.2 has a heap-based buffer over-read in
  ebitmap_match_any (called indirectly from cil_check_neverallow). This occurs
  because there is sometimes a lack of checks for invalid statements in an
  optional block.
severity: low
cvss: 3.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-125
vendor: selinux_project
product: selinux
affected:
  - selinux = 3.2
  - fedora = 35
published: '2021-07-01'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T12:17:14.510'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-36087'
references:
  - url: 'https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32675'
    label: cve@mitre.org
  - url: >-
      https://github.com/SELinuxProject/selinux/commit/340f0eb7f3673e8aacaf0a96cbfcd4d12a405521
    label: cve@mitre.org
  - url: >-
      https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-585.yaml
    label: cve@mitre.org
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U7ZYR3PIJ75N6U2IONJWCKZ5L2NKJTGR/
    label: cve@mitre.org
  - url: >-
      https://lore.kernel.org/selinux/CAEN2sdqJKHvDzPnxS-J8grU8fSf32DDtx=kyh84OsCq_Vm+yaQ%40mail.gmail.com/T/
    label: cve@mitre.org
  - url: 'https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32675'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://github.com/SELinuxProject/selinux/commit/340f0eb7f3673e8aacaf0a96cbfcd4d12a405521
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-585.yaml
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2024/10/msg00021.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U7ZYR3PIJ75N6U2IONJWCKZ5L2NKJTGR/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lore.kernel.org/selinux/CAEN2sdqJKHvDzPnxS-J8grU8fSf32DDtx=kyh84OsCq_Vm+yaQ%40mail.gmail.com/T/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20250207-0004/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-202008.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.00457
epssPercentile: 0.37885
ingestedAt: '2026-10-14T12:29:10.822Z'
---

## Overview

The CIL compiler in SELinux 3.2 has a heap-based buffer over-read in ebitmap_match_any (called indirectly from cil_check_neverallow). This occurs because there is sometimes a lack of checks for invalid statements in an optional block.

## Affected

- `selinux = 3.2`
- `fedora = 35`

## Remediation

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