How severe is CVE-2016-6302?

CVE-2016-6302 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2016-6302 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 26% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-6302?

CVE-2016-6302 primarily affects Openssl. In total, 34 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-6302?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2016-6302 published?

CVE-2016-6302 was published on 2016-09-16 and last updated on 2026-06-17.

CVE-2016-6302

CVE-2016-6302 is a high-severity vulnerability in Openssl with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 26% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 26% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Openssl
Published: 2016-09-16
Last modified: 2026-06-17

Description

The tls_decrypt_ticket function in ssl/t1_lib.c in OpenSSL before 1.1.0 does not consider the HMAC size during validation of the ticket length, which allows remote attackers to cause a denial of service via a ticket that is too short.

Frequently asked questions

What is CVE-2016-6302?: The tls_decrypt_ticket function in ssl/t1_lib.c in OpenSSL before 1.1.0 does not consider the HMAC size during validation of the ticket length, which allows remote attackers to cause a denial of service via a ticket that is too short.
How severe is CVE-2016-6302?: CVE-2016-6302 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2016-6302 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 26% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-6302?: CVE-2016-6302 primarily affects Openssl. In total, 34 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-6302?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-6302 published?: CVE-2016-6302 was published on 2016-09-16 and last updated on 2026-06-17.

References

Affected products (34)

cpe:2.3:a:openssl:openssl:1.0.1:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1a:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1b:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1c:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1d:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1e:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1f:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1g:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1h:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1i:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1j:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1k:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1l:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1m:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1n:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1o:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1p:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1q:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1r:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1s:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.1t:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.2:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.2a:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.2b:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.2c:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.2d:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.2e:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.2f:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.2g:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.0.2h:*:*:*:*:*:*:*
cpe:2.3:o:oracle:linux:6:*:*:*:*:*:*:*
cpe:2.3:o:oracle:linux:7:*:*:*:*:*:*:*
cpe:2.3:o:oracle:solaris:10:*:*:*:*:*:*:*
cpe:2.3:o:oracle:solaris:11.3:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

218.4.91.163 (ipv4-addr)
200.77.172.159 (ipv4-addr)
200.196.50.91 (ipv4-addr)
166.62.41.190 (ipv4-addr)
50.62.22.47 (ipv4-addr)
191.101.33.225 (ipv4-addr)
111.68.102.19 (ipv4-addr)
122.3.106.113 (ipv4-addr)