Public proof of conceptFix available

CVE-2016-6515

A public proof of concept exists; no exploitation attested.

Published2016-08-07
WeaknessCWE-20

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 auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password authentication, which allows remote attackers to cause a denial of service (crypt CPU consumption) via a long string.

Timeline

dates in UTC

2016-08-0721:59CVE publishedNVD
2026-10-2319:23First public proof of conceptPoC-in-GitHub
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-2016-6515?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-6515?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Fedoraproject fedora

Branch	Affected	Fixed in	Source
24.x	= 24	no fix published	NVD

OpenSSH

Branch	Affected	Fixed in	Source
7.2	≤ 7.2	no fix published	NVD

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

Fix

Advisories and patches

github.comPatch

Detection

read 2026-10-23 19:23 UTC

Nuclei template: none so far
Exploit-DB: EDB-40888
Proof-of-concept repositories: 3 repositories, unverifiedopsxcq/exploit-CVE-2016-6515cved-sources/cve-2016-6515jptr218/openssh_dos

Sources

NVDCVSS 3.07.5read 2026-10-23
NVDCVSS 2.07.8read 2026-10-23
NVDweakness (CWE)CWE-20read 2026-10-23
FIRST EPSSEPSS score58.6 %read 2026-10-23
PoC-in-GitHubproof of concept3read 2026-10-23
Exploit-DBdetectionread 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2016-08-07
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2016-6515?

Is CVE-2016-6515 actively exploited?

Active exploitation of CVE-2016-6515 has not been confirmed. Its EPSS score was 58.6% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2016-6515?

CVE-2016-6515 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this product CISA KEV additions, October 2026 Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database