# OpenSSL vulnerabilities & exploitation > As of 2026-10-27, Threadlinqs tracks 9 OpenSSL CVEs, 0 in the CISA Known Exploited Vulnerabilities catalog, linked to 4 tracked threat campaigns. **Data as of:** 2026-10-27 ## Exploitation timeline Threadlinqs has recorded 9 OpenSSL CVEs published between 2026-01-15 and 2026-08-15. The busiest month was 2026-06 (7 new CVEs). None of them is listed in CISA KEV yet. ## Most exploited vulnerabilities Ranked with CISA KEV listings first, then EPSS exploit probability, then CVSS score. Showing 9 of 9 tracked OpenSSL CVEs. - [CVE-2025-15467](https://intel.threadlinqs.com/cve/CVE-2025-15467) — HIGH 8.8 · EPSS 52.4% · 2026-01-27 - [CVE-2026-45447](https://intel.threadlinqs.com/cve/CVE-2026-45447) — HIGH 8.8 · EPSS 4% · 2026-06-09 - [CVE-2026-34182](https://intel.threadlinqs.com/cve/CVE-2026-34182) — CRITICAL 9.1 · EPSS 1.1% · 2026-06-09 - [CVE-2026-34183](https://intel.threadlinqs.com/cve/CVE-2026-34183) — HIGH 7.5 · EPSS 1% · 2026-06-09 - [CVE-2026-42764](https://intel.threadlinqs.com/cve/CVE-2026-42764) — HIGH 7.5 · EPSS 0.8% · 2026-06-09 - [CVE-2026-45445](https://intel.threadlinqs.com/cve/CVE-2026-45445) — HIGH 7.5 · EPSS 0.7% · 2026-06-09 - [CVE-2026-54876](https://intel.threadlinqs.com/cve/CVE-2026-54876) — HIGH 7.5 · EPSS 0.5% · 2026-08-05 - [CVE-2026-42765](https://intel.threadlinqs.com/cve/CVE-2026-42765) — HIGH 7.5 · EPSS 0.5% · 2026-06-09 - [CVE-2026-35188](https://intel.threadlinqs.com/cve/CVE-2026-35188) — MEDIUM 5 · EPSS 0.2% · 2026-06-09 ## Products affected Threadlinqs normalises CPE and CNA product records across all 9 CVEs; 1 distinct OpenSSL product is affected. The most frequently affected: - OpenSSL — 9 CVEs ## Threat activity 4 tracked threat campaigns reference OpenSSL products or exploit OpenSSL CVEs: - [Microsoft September 2026 Patch Tuesday — 999 CVEs, 3 actively exploited zero-days (CVE-2026-85880, CVE-2026-81963, CVE-2026-85046)](https://intel.threadlinqs.com/threat/TL-2026-2407) — CRITICAL — 2026-09-08 - [SDLC Supply Chain Attacks: ChainDrop npm Worm and Developer Pipeline Targeting](https://intel.threadlinqs.com/threat/TL-2026-2104) — HIGH — 2026-08-21 - [CVE-2026-54876 — OpenSSL Client-Side Memory Leak in OCSP Response Checking (Denial of Service)](https://intel.threadlinqs.com/threat/TL-2026-1909) — HIGH — 2026-08-06 - [HollowByte: OpenSSL Pre-Authentication TLS DoS Flaw Bloats Server Memory With 11-Byte Payload](https://intel.threadlinqs.com/threat/TL-2026-1457) — MEDIUM — 2026-07-17 ## How to prioritise OpenSSL patching This order follows the data Threadlinqs holds for OpenSSL, not a generic severity checklist: - No OpenSSL CVE is in CISA KEV yet, so rank by exploit probability instead. - Outside KEV, the highest EPSS scores are [CVE-2025-15467](https://intel.threadlinqs.com/cve/CVE-2025-15467) (52.4%), [CVE-2026-45447](https://intel.threadlinqs.com/cve/CVE-2026-45447) (4%), [CVE-2026-34182](https://intel.threadlinqs.com/cve/CVE-2026-34182) (1.1%). - 1 CVE scores Critical and 7 High on CVSS v3 (maximum 9.1, average 7.7); sequence these after KEV and high-EPSS items. - 2 CVEs have a public exploit or proof of concept recorded, which shortens the time from disclosure to attack. ## About this data Vendor attribution comes from the CNA and CPE product records of each CVE, folded to one vendor name; CVSS, EPSS and KEV status are read from the Threadlinqs CVE catalog; campaign and actor links come from tracked threat records. Counts reflect the data as of 2026-10-27 and refresh daily. Canonical: https://intel.threadlinqs.com/vendors/openssl All vendors: https://intel.threadlinqs.com/vendors Full detection coverage and IOCs via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp