No exploitation reportedFix available

CVE-2016-6306

Q: Is CVE-2016-6306 actively exploited?

Active exploitation of CVE-2016-6306 has not been confirmed. Its EPSS score was 41.7% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2016-6306?

CVE-2016-6306 has a CVSS v3 base score of 5.9 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

No exploitation reported by the sources we read.

Published2016-09-26
WeaknessCWE-125

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

The certificate parser in OpenSSL before 1.0.1u and 1.0.2 before 1.0.2i might allow remote attackers to cause a denial of service (out-of-bounds read) via crafted certificate operations, related to s3_clnt.c and s3_srvr.c.

Timeline

dates in UTC

2016-09-2619:59CVE publishedNVD
2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2016-6306?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-6306?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

OpenSSL

Branch	Affected	Fixed in	Source
1.0	= 1.0.1	no fix published	NVD
1.0	= 1.0.1a	no fix published	NVD
1.0	= 1.0.1b	no fix published	NVD
1.0	= 1.0.1c	no fix published	NVD
1.0	= 1.0.1d	no fix published	NVD
1.0	= 1.0.1e	no fix published	NVD
1.0	= 1.0.1f	no fix published	NVD
1.0	= 1.0.1g	no fix published	NVD
1.0	= 1.0.1h	no fix published	NVD
1.0	= 1.0.1i	no fix published	NVD
1.0	= 1.0.1j	no fix published	NVD
1.0	= 1.0.1k	no fix published	NVD

Node.js

Branch	Affected	Fixed in	Source
6.x	≥ 6.0.0, < 6.7.0	6.7.0	NVD
4.x	≥ 4.2.0, < 4.6.0	4.6.0	NVD
0.12	≥ 0.12.0, < 0.12.16	0.12.16	NVD
0.10	≥ 0.10.0, < 0.10.47	0.10.47	NVD
4.x	≥ 4.0.0, ≤ 4.1.2	no fix published	NVD
5.x	≥ 5.0.0, ≤ 5.12.0	no fix published	NVD

Canonical ubuntu linux

Branch	Affected	Fixed in	Source
12.4	= 12.04	no fix published	NVD
14.4	= 14.04	no fix published	NVD
16.4	= 16.04	no fix published	NVD

6 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

RHSA-2016:1940 Red Hat Product Security151 products fixed
Red Hat Security Advisory: openssl security update

Full record on NVD

Fix

Vendor fix Red Hat Product Security RHSA-2016:1940 · 151 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted.

Advisories and patches

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.15.9read 2026-10-23
NVDCVSS 2.04.3read 2026-10-23
NVDweakness (CWE)CWE-125read 2026-10-23
FIRST EPSSEPSS score41.7 %read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2016-09-26
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2016-6306?

Is CVE-2016-6306 actively exploited?

Active exploitation of CVE-2016-6306 has not been confirmed. Its EPSS score was 41.7% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2016-6306?

CVE-2016-6306 has a CVSS v3 base score of 5.9 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

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