CVE-2015-3146

The (1) SSH_MSG_NEWKEYS and (2) SSH_MSG_KEXDH_REPLY packet handlers in package_cb.c in libssh before 0.6.5 do not properly validate state, which allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via a crafted SSH packet.

Published: 2016-04-13 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-3146 is rated Moderate Risk (62.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.91%). EPSS rose +1.51% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2015-3146

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.40% 3.91% +1.51%
2 2026-05-13 2.84% 2.40% -0.44%
3 2025-12-28 — 2.84% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-3146

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2015-3146

OS Trackers for CVE-2015-3146

vendor priority summary link
debian not yet assigned CVE-2015-3146 not yet assigned priority: Debian including 1 source packages (libssh), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-3146
redhat medium — https://access.redhat.com/security/cve/CVE-2015-3146
suse high CVE-2015-3146 severity important: SUSE including 284 source package names (14.28:libssh4-0.6.3-8.1, amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, …), 350 product×package rows across 49 product lines (Container suse/sles12sp4, SUSE Linux Enterprise Desktop 11 SP3, … (49 product lines)): Fixed 168, Known Affected 157, Known Not Affected 25. https://www.suse.com/security/cve/CVE-2015-3146/
ubuntu low CVE-2015-3146 low priority: Ubuntu including 1 source packages (libssh), 6 status rows across 6 suites (precise, trusty, upstream, utopic, vivid, wily): released 4, ignored 2. https://ubuntu.com/security/CVE-2015-3146

NVD evaluator notes for CVE-2015-3146

Comment: <a href="http://cwe.mitre.org/data/definitions/476.html">CWE-476: NULL Pointer Dereference</a>

Affected software / configurations for CVE-2015-3146

Vendor Product Version Raw CPE
libssh libssh <= 0.6.4 cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 15.10 cpe:2.3:o:canonical:ubuntu_linux:15.10:*:*:*:*:*:*:*
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
fedoraproject fedora 21 cpe:2.3:o:fedoraproject:fedora:21:*:*:*:*:*:*:*
fedoraproject fedora 22 cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:*

References for CVE-2015-3146

cvelogic Threat Intelligence