What is CVE-2016-6309?
statem/statem.c in OpenSSL 1.1.0a does not consider memory-block movement after a realloc call, which allows remote attackers to cause a denial of service (use-after-free) or possibly execute arbitrary code via a crafted TLS session.
The identifier was first published 3683 days ago.
Severity and exploitation probability
- EPSS (FIRST)
- 70.2% probability of exploitation in the next 30 days, higher than 99.3% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2016-09-26, last modified 2024-08-06
Is CVE-2016-6309 being exploited?
Weaponised exploit code for CVE-2016-6309 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 38 in the Threadlinqs vulnerability feed.
- trickest/cve (trickest)
Affected products and versions
No affected-product or package list has been recorded for CVE-2016-6309 in the tracked sources. The vendor advisory and the references below are the authoritative statement of what is affected.
How to fix CVE-2016-6309
No vendor patch reference has been recorded for CVE-2016-6309 in the tracked sources. Follow the references below for a fix, and treat any affected deployment as exposed until the vendor states otherwise.
Threat activity tracking CVE-2016-6309
1 tracked threat in the Threadlinqs corpus references CVE-2016-6309, either in the campaign’s CVE list or as an indicator on the campaign record.
- OpenSSL "HollowByte" TLS Handshake Memory-Amplification DoS (No CVE Assigned) — MEDIUM · 2026-07-17
Sources
Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on .
Vendor advisory and patch
Vulnerability database entry
Showing 7 of 14 recorded references.