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Fencer Intel
critical 9.9

CVE-2026-122193 json

OS command injection in the example SSM documents in Trusted Remote Execution (REX)

published 3d ago modified 3d ago also EUVD-2026-118379

cvss
9.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

OS command injection in the example SSM document provisioning script in Trusted Remote Execution (REX) before 2026-07-28 might allow an authenticated remote user who is permitted to invoke the Rex-RO or Rex-RW SSM document to execute arbitrary commands as root on the managed instance, bypassing Cedar policy enforcement.

To remediate this issue, users should delete any Rex-RO and Rex-RW SSM documents created from the example script, in each account and Region where it was run.

Is CVE-2026-122193 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
3d ago

Exploit prediction

1.63% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:L/SA:N
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • AWS trusted-remote-execution

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.