← Vulnerability feed

Vulnerability record · CVE-2026-35189 · published 29 September 2026

CVE-2026-35189: Openssl allocation without limits vulnerability

OOpenssl · Openssl

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.

5.3 CVSS 3.1 Medium EPSS 0.35% · top 70.4% CWE-770 · Allocation without limits
5.3CVSS 3.1 base score
0.35%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References
10 Nov 2026Last modified by NVD

Description

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/openssl/openssl/commit/2b93c73b2c70ddc4c61c5e4bfaaa6bd71379eb84 Patch
https://github.com/openssl/openssl/commit/3842516cc15e8b2cf55747011045e77547e71d89 Patch
https://github.com/openssl/openssl/commit/8e0efc7549b7ff8246d40e585e3fd604f728473f Patch
https://github.com/openssl/openssl/commit/c72ae182cac17a82e4246c6ecd4e9c4ec3586ec9 Patch
https://openssl-library.org/news/secadv/20260929.txt Vendor Advisory
https://cert-portal.siemens.com/productcert/html/ssa-457936.html

Track CVE-2026-35189 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

7.5CVE-2014-0160OpenSSL TLS/DTLS Heartbeat Extension Out-of-Bounds Read (Heartbleed)OpenSSL 1.0.1 before 1.0.1g mishandles Heartbeat Extension packets in its TLS and DTLS implementations, causing an out-of-bounds read of process memo…KEVEPSS 100%analysed10.0CVE-2009-3245Openssl improper input validation vulnerabilityOpenSSL before 0.9.8m does not check for a NULL return value from bn_wexpand function calls in (1) crypto/bn/bn_div.c, (2) crypto/bn/bn_gf2m.c, (3) c…EPSS 5.8%10.0CVE-2006-3738OpenSSL SSL_get_shared_ciphers buffer overflow via long cipher listOpenSSL versions before 0.9.7l and 0.9.8d contain a buffer overflow in the SSL_get_shared_ciphers function, triggered by a long list of ciphers. The …EPSS 50%analysed9.8CVE-2026-63073Openssl vulnerabilityIssue summary: OpenSSL CMP response validation passed an unexpected response sender distinguished name directly as the format string to `ERR_raise_da…EPSS 1.2%9.8CVE-2026-31789Openssl out-of-bounds write vulnerabilityIssue summary: Converting an excessively large OCTET STRING value to a hexadecimal string leads to a heap buffer overflow on 32 bit platforms. Impact…EPSS 0.25%9.8CVE-2025-9230Openssl out-of-bounds read vulnerabilityIssue summary: An application trying to decrypt CMS messages encrypted using password based encryption can trigger an out-of-bounds read and write. I…EPSS 1.8%9.8CVE-2024-4741Openssl use after free vulnerabilityIssue summary: Calling the OpenSSL API function SSL_free_buffers may cause memory to be accessed that was previously freed in some situations Impact …EPSS 3.3%9.8CVE-2022-2274OpenSSL 3.0.4 RSA AVX512IFMA memory corruptionOpenSSL 3.0.4 introduced a bug in the RSA implementation for X86_64 CPUs supporting AVX512IFMA instructions, causing 2048-bit private key operations …EPSS 48%analysed

Source: NIST National Vulnerability Database (record CVE-2026-35189), CISA KEV, FIRST EPSS (scores of 2026-11-13). This page is refreshed as NVD updates the record.