CVE-2019-17498 — In libssh2 v1.9.0 and earlier versions, the SSH_MSG_DISCONNECT logic in packet.c has an integer...
In libssh2 v1.9.0 and earlier versions, the SSH_MSG_DISCONNECT logic in packet.c has an integer overflow in a bounds check, enabling an attacker to specify an arbitrary (out-of-bounds) offset for a subsequent memory read. A crafted SSH server may be able to disclose sensitive information or cause a denial of service condition on the client system when a user connects to the server.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 3.8% (30-day exploitation probability)+13
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Debian Debian Linux, Fedoraproject Fedora, Libssh2 Libssh2…).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Debian | Debian Linux | version 8.0version 9.0 | Vulnerable | NIST National Vulnerability Database |
| Fedoraproject | Fedora | version 30version 31 | Vulnerable | NIST National Vulnerability Database |
| Libssh2 | Libssh2 | ≤ 1.9.0 | Vulnerable | NIST National Vulnerability Database |
| Netapp | Active Iq Unified Manager | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Bootstrap Os | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Element Software | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Hci Management Node | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Ontap Select Deploy Administration Utility | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Solidfire | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Opensuse | Leap | version 15.1 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.1 | CVSS 3.1 | High | 2.8 | 5.2 | nvd@nist.gov via NIST National Vulnerability Database |
| 8.1 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 5.8 | CVSS 2.0 | Medium | 8.6 | 4.9 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 3.81%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Fix documented
- Affected products added · libssh2/libssh2, fedoraproject/fedora, opensuse/leap, debian/debian linux, netapp/active iq unified manager, netapp/elem
- CVSS changed · 8.1
- Source status changed · → Modified
- Record created in this database
- 2019
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
18 on the record
- github.com/libssh2/libssh2/commit/dedcbd106f8e52d5586b0205bc7677e4c9868f9c
- lists.debian.org/debian-lts-announce/2021/12/msg00013.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22H4
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/22H4Q5
- lists.debian.org/debian-lts-announce/2019/11/msg00010.html
- github.com/advisories/GHSA-h2hf-mx7w-fhwm
- security.netapp.com/advisory/ntap-20220909-0004/
- nvd.nist.gov/vuln/detail/CVE-2019-17498
- github.com/libssh2/libssh2/pull/402/commits/1c6fa92b77e34d089493fe6d3e2c6c877585
- lists.debian.org/debian-lts-announce/2023/09/msg00006.html
- github.com/libssh2/libssh2/blob/42d37aa63129a1b2644bf6495198923534322d64/src/pac
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00026.html
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TY7EEE
- cert-portal.siemens.com/productcert/html/ssa-398330.html
- packetstormsecurity.com/files/172835/libssh2-1.9.0-Out-Of-Bounds-Read.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TY7E
- github.com/kevinbackhouse/SecurityExploits/tree/8cbdbbe6363510f7d9ceec685373da12
- blog.semmle.com/libssh2-integer-overflow-CVE-2019-17498/
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-12996 A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote... Jul 30, 2026
- High CVE-2026-58050 libssh2 - Integer Overflow in publickey Subsystem Attribute Allocation Jun 27, 2026
- Medium CVE-2026-58051 libssh2 - Free of Uninitialized Pointer in publickey List Cleanup Jun 27, 2026
- Medium CVE-2026-56968 Use of Uninitialized Resource in Gnu Sasl Jun 23, 2026
- Medium CVE-2025-15661 libssh2 - Heap Buffer Over-read via sftp_symlink() in sftp.c Jun 18, 2026
- High CVE-2026-55200 libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c Jun 17, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2019-17498 is "In libssh2 v1.9.0 and earlier versions, the SSH_MSG_DISCONNECT logic in packet.c has an integer...", rated High. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.1 describes technical severity. EPSS 3.81% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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