---
id: CVE-2026-35189
title: |-
  Issue summary: A certificate with many nameRelativeToCRLIssuer CRL
  distribution points causes disproportionate heap growth when OpenSSL caches
  X.509 extensions.

  Impact summary: Receiving a crafted certificate from a malicious peer can l…
summary: |-
  Issue summary: A certificate with many nameRelativeToCRLIssuer CRL
  distribution points causes disproportionate heap growth when OpenSSL caches
  X.509 extensions.

  Impact summary: Receiving a crafted certificate from a malicious peer can l…
severity: none
cwe:
  - CWE-770
vendor: OpenSSL
product: OpenSSL
affected:
  - OpenSSL >= 4.0.0 < 4.0.3
  - OpenSSL >= 3.6.0 < 3.6.5
  - OpenSSL >= 3.5.0 < 3.5.9
  - OpenSSL >= 3.4.0 < 3.4.8
  - OpenSSL >= 3.0.0 < 3.0.23
  - OpenSSL >= 1.1.1 < 1.1.1zj
  - OpenSSL >= 1.0.2 < 1.0.2zs
published: '2026-09-29'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T16:17:07.330'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-35189'
references:
  - url: >-
      https://github.com/openssl/openssl/commit/2b93c73b2c70ddc4c61c5e4bfaaa6bd71379eb84
    label: openssl-security@openssl.org
  - url: >-
      https://github.com/openssl/openssl/commit/3842516cc15e8b2cf55747011045e77547e71d89
    label: openssl-security@openssl.org
  - url: >-
      https://github.com/openssl/openssl/commit/8e0efc7549b7ff8246d40e585e3fd604f728473f
    label: openssl-security@openssl.org
  - url: >-
      https://github.com/openssl/openssl/commit/c72ae182cac17a82e4246c6ecd4e9c4ec3586ec9
    label: openssl-security@openssl.org
  - url: 'https://openssl-library.org/news/secadv/20260929.txt'
    label: openssl-security@openssl.org
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-29T16:39:33.264Z'
---

## Overview

Issue summary: A certificate with many nameRelativeToCRLIssuer CRL
distribution points causes disproportionate heap growth when OpenSSL caches
X.509 extensions.

Impact summary: Receiving a crafted certificate from a malicious peer can lead
to significant memory pressure and possible Denial of Service in clients or
in servers that solicit client certificates.

CWE: CWE-770: Allocation of Resources Without Limits or Throttling

Description: A certificate or a set of certificates that fits under the limit for
size of certificates accepted from the peer (~100 KiB) can result in allocation
of several hundred MiB of resident memory on the receiving side
during a normal TLS handshake.  This may be enough to crash the client or
server, if multiple concurrent connections lead to similarly large memory
allocations.

The fix postpones processing of the CRL distribution points extensions in
certificates to the time when the processed value is required for CRL processing.
This avoids keeping large memory allocations for a long time when such
certificates are received.

FIPS impact: no
The affected code is outside the FIPS module boundary.

## Remediation

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