PT-2026-47833 · Openssl · Openssl

Aaron Grattafiori + 3 · CVE-2026-35188 · Published 2026-06-09 · Updated 2026-07-15

Positive Technologies (AI Summary)

CVSS v3.1

5.0

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions OpenSSL (affected versions not specified)

Description A malicious server can exploit TLS OCSP stapling by delivering a crafted response through the status request extension. This triggers a double-free in the client's certificate verification path when the stapled response is checked. A double-free occurs when a program attempts to free the same memory location twice, which can corrupt heap memory. This may lead to a Denial of Service, attacker-controlled code execution, or other undefined behavior. OCSP stapling is not enabled by default.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability. As a temporary workaround, consider disabling OCSP stapling to minimize the risk of exploitation.

Exploit

DoS

Double Free

Weakness Enumeration

CWE-415

Related Identifiers

CVE-2026-35188

ZDI-26-425

Affected Products

Openssl

References · 15

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35188.json · Exploit
• https://github.com/openssl/openssl/commit/78d0154cffda03aaaac63a087cc523a6b35fa8fd · Patch
• https://github.com/openssl/openssl/commit/131145d25659e8749a9ed1afb383484854cffb78 · Patch
• https://openssl-library.org/news/secadv/20260609.txt · Vendor Advisory
• https://zerodayinitiative.com/advisories/ZDI-26-425 · Security Note
• ❌ https://github.com/openssl/security/commit/131145d25659e8749a9ed1afb383484854cffb78 · Patch, Deleted
• https://cve.org/CVERecord?id=CVE-2026-35188 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-35188 · Security Note
• https://ubuntu.com/security/CVE-2026-35188 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-35188 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-35188 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-35188 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-35188 · Vendor Advisory
• ❌ https://github.com/openssl/security/commit/78d0154cffda03aaaac63a087cc523a6b35fa8fd · Patch, Deleted
• https://t.me/cveNotify/166804 · Telegram Post