High 7.5Published May 4, 2017

CVE-2017-3733During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (d…

Updated under an hour ago (Nov 2, 2026, 12:10 AM ET)

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It affects openssl and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

CVSS: 7.5 HIGH (v3.0, NVD)CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-20
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Modified
Record last updated: Jun 16, 2026
First seen by InfoSec Signals: Nov 1, 2026

Affected products

Affected products

openssl openssl openssl:openssl	1.1.0; 1.1.0a; 1.1.0b; 1.1.0c; 1.1.0d	NVD
hp operations_agent hp:operations_agent	11.14; 11.15	NVD

References

References

http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.securityfocus.com/bid/96269	third-party-advisory, vdb-entry
http://www.securitytracker.com/id/1037846
https://github.com/openssl/openssl/commit/4ad93618d26a3ea23d36ad5498ff4f59eff3a4d2
https://h20566.www2.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbgn03728en_us	third-party-advisory, vdb-entry
https://www.openssl.org/news/secadv/20170216.txt	vendor-advisory
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.