CVE-2026-35189
Published:September 29, 2026
Updated:October 15, 2026
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.
Affected Packages
openssl (CONAN):
Affected version(s) >=3.5.0 <3.5.9Fix Suggestion:
Update to version 3.5.9openssl (CONAN):
Affected version(s) >=3.4.0 <3.4.8Fix Suggestion:
Update to version 3.4.8openssl (CONAN):
Affected version(s) >=3.6.0 <3.6.5Fix Suggestion:
Update to version 3.6.5openssl (CONAN):
Affected version(s) >=4.0.1 <4.0.3Fix Suggestion:
Update to version 4.0.3openssl (CONDA):
Affected version(s) >=3.5.0 <3.5.9Fix Suggestion:
Update to version 3.5.9openssl (CONDA):
Affected version(s) >=4.0.1 <4.0.3Fix Suggestion:
Update to version 4.0.3openssl (CONDA):
Affected version(s) >=3.6.0 <3.6.5Fix Suggestion:
Update to version 3.6.5openssl (CONDA):
Affected version(s) >=3.4.0 <3.4.8Fix Suggestion:
Update to version 3.4.8https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.5.0 <openssl-3.5.9Fix Suggestion:
Update to version openssl-3.5.9https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.4.0 <openssl-3.4.8Fix Suggestion:
Update to version openssl-3.4.8https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-4.0.0 <openssl-4.0.3Fix Suggestion:
Update to version openssl-4.0.3https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.6.0 <openssl-3.6.5Fix Suggestion:
Update to version openssl-3.6.5Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
Allocation of Resources Without Limits or Throttling
EPSS
Base Score:
0.27