What it is
CVE-2026-123158 is an unauthenticated vulnerability affecting OpenBSD OpenSSH.
Vulnerability report
Exploitation Attempts Observed
Confirmed Confidence
Not in CISA KEV
CVE-2026-123158
OpenSSH Authentication Bypass
OpenBSD / OpenSSH · affected before 10.6p2
- Severity
- CVSS 8.1 · High
- Confidence
- Confirmed
- Exploit status
- Exploitation Attempts Observed in the Wild
- EPSS
- —
- First observed
- 06 Nov 2026
- Last observed
- 06 Nov 2026
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Have exploitation attempts been observed?
Yes. Previdian sensors have observed 8 exploitation attempts, 1 unique attacker IP, and 1 country targeting CVE-2026-123158. First observed Nov 06, 2026. Confidence is confirmed.
Who is affected?
OpenBSD / OpenSSH affected before 10.6p2.
What should we do?
Patch immediately, validate internet-facing exposure, and monitor for matching requests.
Overview
OpenSSH Authentication Bypass
sshd in OpenSSH before 10.6p2 on Linux, when musl libc is used without PAM, lacks a workaround for a password authentication bypass (related to misinterpretation of whether a string is intended to be a password hash). For some configurations of accounts, any password between 256 and 1024 characters succeeds.
An example of a platform using musl libc without PAM is Alpine Linux.
Vendor
Product
Affected
Status
OpenBSD
Affected
OpenSSH
Before 10.6p2
Affected
- Published
- 05 Nov 2026
- Exploitation Attempts Reported
- 05 Nov 2026
- Attack vector
- Remote
- Complexity
- High
- Privileges
- None
- User interaction
- None
Tags
linux
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-123158
- openssh.org/releasenotes.html openssh.org · CVE Record https://www.openssh.org/releasenotes.html#10.6p2
- GitHub — openssh/openssh-portable github.com · CVE Record https://github.com/openssh/openssh-portable/commit/4353fdc43ef646c43a...
- news.ycombinator.com/item news.ycombinator.com · CVE Record https://news.ycombinator.com/item?id=50377976
- news.ycombinator.com/item news.ycombinator.com · CVE Record https://news.ycombinator.com/item?id=50378228
- marc.info marc.info · CVE Record https://marc.info/?l=openssh-unix-dev&m=179388064263131&w=2
- hachyderm.io/@damienmiller/117563026759098135 hachyderm.io · CVE Record https://hachyderm.io/@damienmiller/117563026759098135
- GitHub — predkambrij/sshhole-repro github.com · CVE Record https://github.com/predkambrij/sshhole-repro
- GitHub — leonjza/sshhole-lab github.com · CVE Record https://github.com/leonjza/sshhole-lab
Exploitation evidence
Evidence of exploitation attempts
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploitation Attempts Observed in the Wild
Previdian
Previdian sensors observed exploitation attempts targeting this vulnerability.
Exploitation Attempts Observed
Previdian sensor
Previdian sensors observed exploitation attempts targeting this vulnerability.
Proof of concept available
CVE
Public scanner or PoC coverage increases practical exploitability.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the Previdian Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| Previdian Sensors First | 2026-11-06 09:53 UTC |
Operational indicators for this CVE are listed under Detection.
Sensor telemetry
Previdian Sensor Observations
Previdian sensor observations are exploitation attempts targeting this vulnerability. They do not show that the target was vulnerable or that the attempt succeeded. The cards and chart show volume, unique attackers, and daily activity.
8
Attempts observed
1
Unique attacker IPs
1
Attacker countries
JP
1
Sensors observed
CVE-2026-123158 exploitation attempts over the last 7 days
Daily events observed by Previdian sensors
Updated 06 Nov 2026
31 Oct
1 Nov
2 Nov
3 Nov
4 Nov
5 Nov
6 Nov
First observed 06 Nov 2026 · Last observed 06 Nov 2026
Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Scanner coverage
No scanner integrations recorded yet.
Virtual patch status
No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Attacker IP Indicators
Attacker IP indicators observed · available in Pro and Enterprise.
Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.
Learn about Pro API accessRisk and context
Severity, weaknesses, and research context
CVSS v3.1
8.1
High
Potential damage if exploited. Separate from whether attackers are using it.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
—
Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.
Recent mention · SOCRadar
sshole: OpenSSH Fixes Password Bypass on Alpine Linux
OpenSSH has shipped an emergency release, version 10.6p2, to stop a password bypass that lets a remote attacker log in to accounts that have no password set. The flaw, tracked as CVE-2026-123158 and nicknamed “sshole,” affects Linux systems that run OpenSSH on the musl C...
Read full advisoryPotential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
HackSpeak/CVE-2026-123158
github · Created 2026-11-06 10:53:29 UTC · 1 stars · AI assessment 86%
OpenSSH + musl password authentication bypass (sshole) checker: local precondition audit + remote verification; for authorized testing
Maalfer/CVE-2026-123158
github · Created 2026-11-06 08:01:34 UTC · 0 stars · AI assessment 84%
Exploit para explotar la vulnerabilidad CVE-2026-123158 (conocida como sshole).
CVE-2026-123158 Exploit: sshhole Auth Bypass
1dayexploit · Created 2026-11-05 20:16:30 UTC
sshhole (CVE-2026-123158): OpenSSH pre-auth authentication bypass on musl libc. Any password 257-1024 bytes bypasses auth for disabled accounts. Remote account takeover, uid 0 possible.
CVE Record exploit — sshhole.com
cve · Created Unknown
Timeline
From disclosure to observed exploitation attempts
-
00:05 UTC
Indicator of compromise added
Indicators of compromise recorded
-
00:05 UTC
Observed by Previdian sensors
Previdian sensors observed exploitation attempts targeting this vulnerability.
-
18:12 UTC
CVE ID assigned
Previously tracked as VULN-2026-0006
-
17:30 UTC
Public PoC available
Public proof-of-concept code published
-
15:46 UTC
CVE published
Vulnerability disclosed publicly
-
15:46 UTC
CVE ID reserved
Identifier reserved by the CNA
-
15:19 UTC
Added to the Previdian watchlist
Pro and Enterprise Watch users had 1 day of early warning before Previdian KEV.
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2026-123158
Sample API response{
"cve_id": "CVE-2026-123158",
"confidence": "Confirmed",
"cvss_score": 8.1,
"cvss_estimated": false,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": true
},
"sensor_telemetry": { "attempts": 8, "sensors": 1 }
}