CVE-2019-16905
No exploitation reported by the sources we read.
- Published2019-10-09
- Fixed in8.1
- WeaknessCWE-190
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « 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
OpenSSH 7.7 through 7.9 and 8.x before 8.1, when compiled with an experimental key type, has a pre-authentication integer overflow if a client or server is configured to use a crafted XMSS key. This leads to memory corruption and local code execution because of an error in the XMSS key parsing algorithm. NOTE: the XMSS implementation is considered experimental in all released OpenSSH versions, and there is no supported way to enable it when building portable OpenSSH.
Timeline
dates in UTC- 2019-10-0920:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-28 09:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2019-16905?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2019-16905?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 8.x | ≥ 8.0, < 8.1 | 8.1 | NVD |
| 7.x | ≥ 7.7, ≤ 7.9 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| — | all versions | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| — | all versions | no fix published | NVD |
2 more products in the sources.
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Vendor advisories
- CVE-2019-16905 Red Hat Product Security
openssh: an integer overflow in the private key parsing code for the XMSS key type
Siemens SIMATIC S7-1500
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) · +2 more
SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.0 < V3.1.5 · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.0 < V3.1.5 · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.0 < V3.1.5 · +2 more
Siemens SCALANCE X-200RNA Switch Devices
SCALANCE X204RNA (HSR) (6GK5204-0BA00-2MB2) · SCALANCE X204RNA (PRP) (6GK5204-0BA00-2KB2) · SCALANCE X204RNA EEC (HSR) (6GK5204-0BS00-2NA3) · +2 more
SSA-412672: Multiple OpenSSL and OpenSSH Vulnerabilities in SCALANCE X-200RNA Switch Devices before V3.2.7
SCALANCE X204RNA (HSR) (6GK5204-0BA00-2MB2) · SCALANCE X204RNA (PRP) (6GK5204-0BA00-2KB2) · SCALANCE X204RNA EEC (HSR) (6GK5204-0BS00-2NA3) · +2 more
Fix
- Update OpenSSH to 8.1
- Vendor fix CISA ICSA-23-348-10 · 5 productsUpdate to V3.1.5 or later version
- Vendor fix Siemens ProductCERT SSA-398330 · 1 productUpdate to V3.1.5 or later version
- Vendor fix Siemens ProductCERT SSA-412672 · 5 productsUpdate to V3.2.7 or later version
- Vendor fix CISA ICSA-22-349-21 · 5 productsUpdate to V3.2.7 or later version
- Workaround from the vendor Red Hat Product Security CVE-2019-16905 · 27 productsThis flaw is triggered when parsing XMSS private keys. XMSS is a PQC (Post-quantum cryptography) algorithm and its use is currently experimental. Other key types or any other OpenSSH functionality are not affected by this flaw. A possible mitigation for this flaw is to NOT use XMSS keys for SSH.
- Mitigation from the vendor CISA ICSA-23-348-10 · 5 productsOnly build and run applications from trusted sources.
Advisories and patches
- cvsweb.openbsd.orgRelease Notes · Vendor Advisory
- cvsweb.openbsd.orgPatch
- www.openssh.comRelease Notes
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
- NVDCVSS 3.17.8read 2026-10-23
- NVDCVSS 2.04.4read 2026-10-23
- NVDweakness (CWE)CWE-190read 2026-10-23
- FIRST EPSSEPSS score2.2 %2026-10-26
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Published
- 2019-10-09
- Last Modified
- 2026-10-14
- NVD status
- Modified
Frequently asked questions
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