CVE-2016-8858: openbsd openssh Resource Management Errors
Vulnerability summary
CVE-2016-8858 is a high (CVSS 7.8) Resource Management Errors vulnerability in openbsd openssh. EPSS estimates a 29.46% chance of exploitation in the next 30 days, higher than 98.1% of scored vulnerabilities.
Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 29% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 8 · Related 8Timeline
- 09-12-2016PublishedVulnerability first disclosed.
- 29-05-2026Last modifiedVulnerability information updated.
Description
The kex_input_kexinit function in kex.c in OpenSSH 6.x and 7.x through 7.3 allows remote attackers to cause a denial of service (memory consumption) by sending many duplicate KEXINIT requests. NOTE: a third party reports that "OpenSSH upstream does not consider this as a security issue."
CVSS metrics
7 scores · 4 sources · 3 versions- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
29.46%
Chance of exploitation in the next 30 days
Percentile
98%
Versus all other CVEs
30-day change
No change 0.00 pp
From 29.46% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- openssh< 1:7.3p1-2
Openbsd1 product
- openssh6.8 | 6.9 | 7.0 | 7.1 | 7.2 | 7.3
Ubuntu1 product
- opensshAll versions (No fix recorded)
3 vendors · 3 products
References
17 links- security.netapp.com/advisory/ntap-20180201-0001/Third Party Advisory
- cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c.diff?r1=1.126&r2=1.127&f=hIssue TrackingVendor Advisory
- github.com/openssh/openssh-portable/commit/ec165c392ca54317dbe3064a8c200de6531e89adIssue TrackingPatchThird Party Advisory
Show all 17 references
- bugzilla.redhat.com/show_bug.cgi?id=1384860Issue Tracking
- cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/kex.c?rev=1.127&content-type=text/x-cvsweb-markupIssue TrackingVendor Advisory
