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Vulnerability record · CVE-2016-6305 · published 26 September 2016

CVE-2016-6305: Openssl improper input validation vulnerability

OOpenssl · Openssl

The ssl3_read_bytes function in record/rec_layer_s3.c in OpenSSL 1.1.0 before 1.1.0a allows remote attackers to cause a denial of service (infinite loop) by triggering a zero-length record in an SSL_peek call.

7.5 CVSS 3.0 High EPSS 16% · top 3.2% CWE-20 · Improper input validation
7.5CVSS 3.0 base score, v2 5.0
16%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
36References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

The ssl3_read_bytes function in record/rec_layer_s3.c in OpenSSL 1.1.0 before 1.1.0a allows remote attackers to cause a denial of service (infinite loop) by triggering a zero-length record in an SSL_peek call.

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10759
http://www-01.ibm.com/support/docview.wss?uid=swg21995039
http://www.oracle.com/technetwork/security-advisory/cpuapr2018-3678067.html
http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html
http://www.oracle.com/technetwork/security-advisory/cpujul2017-3236622.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.securityfocus.com/bid/93149
http://www.securitytracker.com/id/1036879
https://bto.bluecoat.com/security-advisory/sa132
https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
https://git.openssl.org/?p=openssl.git%3Ba=commit%3Bh=63658103d4441924f8dbfc517b99bb54758a98b9
https://github.com/openssl/openssl/issues/1563 ExploitIssue Tracking
https://security.gentoo.org/glsa/201612-16
https://www.openssl.org/news/secadv/20160922.txt Vendor Advisory
https://www.tenable.com/security/tns-2016-16
https://www.tenable.com/security/tns-2016-20
https://www.tenable.com/security/tns-2016-21
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10759
http://www-01.ibm.com/support/docview.wss?uid=swg21995039
http://www.oracle.com/technetwork/security-advisory/cpuapr2018-3678067.html
http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html
http://www.oracle.com/technetwork/security-advisory/cpujul2017-3236622.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.securityfocus.com/bid/93149
http://www.securitytracker.com/id/1036879
https://bto.bluecoat.com/security-advisory/sa132
https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
https://git.openssl.org/?p=openssl.git%3Ba=commit%3Bh=63658103d4441924f8dbfc517b99bb54758a98b9
https://github.com/openssl/openssl/issues/1563 ExploitIssue Tracking
https://security.gentoo.org/glsa/201612-16
https://www.openssl.org/news/secadv/20160922.txt Vendor Advisory
https://www.tenable.com/security/tns-2016-16
https://www.tenable.com/security/tns-2016-20
https://www.tenable.com/security/tns-2016-21

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2016-6305), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.