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Fencer Vulns
critical 9.8

CVE-2016-6309 in the critical feed json

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 de…

published 2016-09-26 10 y ago modified 2026-06-17 4 mo ago also EUVD-2016-7238

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
70.2%
EPSS 70.2% chance of exploitation in 30 days, percentile 99.3%
public exploits
0
none known

Summary

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-6309 updated cvss 9.8

openssl: Use After Free for large message sizes

  • Red Hat Enterprise Linux 4 openssl Red Hat Enterprise Linux 5 openssl, openssl097a Red Hat Enterprise Linux 6 openssl, openssl098e, openssl-perl Red Hat Enterprise Linux 7 openssl, openssl098e, openssl-libs, openssl-perl Red Hat JBoss Enterprise Application Platform 5 openssl Red Hat JBoss Enterprise Application Platform 6 openssl
    +3 more products
    Red Hat JBoss Enterprise Web Server 1 openssl Red Hat JBoss Enterprise Web Server 2 openssl Red Hat JBoss Enterprise Web Server 3 openssl
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

70.22% chance of exploitation in the next 30 days, higher than 99.3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.