VulnerabilityPublished 21 Oct 2026Updated 28 Oct 2026

CVE-2026-94140: Rex versions through 1.16.1 for Perl accept an unknown SSH host key for remote rsync transfers

Affects rexSource GCVE Database

Authoritative record:CVE-2026-94140· High

Not known to be exploited.

Data as of 28 Oct 2026, 22:28 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.10rex`pkg:deb/ubuntu/rex?arch=source&distro=stonking`Other threats	Affected =1.16.1-1	Fixed in–
Ubuntu 26.04 LTSrex`pkg:deb/ubuntu/rex?arch=source&distro=resolute`Other threats	Affected =1.16.0-1 =1.16.1-1	Fixed in–
Ubuntu 24.04 LTSrex`pkg:deb/ubuntu/rex?arch=source&distro=noble`Other threats	Affected =1.14.3-1	Fixed in–
Ubuntu 22.04 LTSrex`pkg:deb/ubuntu/rex?arch=source&distro=jammy`Other threats	Affected =1.13.3-1 =1.13.4-1	Fixed in–
Ubuntu 20.04 LTSrex`pkg:deb/ubuntu/rex?arch=source&distro=focal`Other threats	Affected 1.6.0-1 – 1.8.1-1 4 affected builds	Fixed in–
Ubuntu 18.04 LTSrex`pkg:deb/ubuntu/rex?arch=source&distro=bionic`Other threats	Affected =1.5.0-1 =1.6.0-1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

Rex versions through 1.16.1 for Perl accept an unknown SSH host key for remote rsync transfers because sync hardcodes StrictHostKeyChecking=no. Every remote branch of sync builds its ssh command with that option, for password authentication, for private-key authentication and for the fallback. The ssh options a caller sets through set_openssh_opt reach the OpenSSH transport but not this command, so there is no configuration that restores host key checking for the transfer. An attacker who can redirect the connection before the real host key is known presents their own and the transfer proceeds: under password authentication sync sends the connection password to that server, an upload writes the selected local files to it, and a download writes what it returns to the local destination.

References

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