CVE-2026-1386

Host file overwrite via jailer destination symlink

Published Jan 23, 2026 · Updated Jan 23, 2026

Symlink following in the AWS Firecracker jailer 1.13.1 and earlier and 1.14.0 allows local users to overwrite arbitrary host files. During startup, the jailer copies its executable into a pre-created chroot destination without rejecting symbolic or hard links, so a crafted destination redirects the root-run copy to a host file. Exploitation requires write access to the pre-created jailer directory and a jailer process running as root; the documented result is host-file modification and possible service interruption.

CVSS severity6.0
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Symlink following in the AWS Firecracker jailer 1.13.1 and earlier and 1.14.0 allows local users to overwrite arbitrary host files. During startup, the jailer copies its executable into a pre-created chroot destination without rejecting symbolic or hard links, so a crafted destination redirects the root-run copy to a host file. Exploitation requires write access to the pre-created jailer directory and a jailer process running as root; the documented result is host-file modification and possible service interruption.

The record

CVE
CVE-2026-1386
Published
Jan 23, 2026
Updated
Jan 23, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-61, CAPEC-27, T1565.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.0AmazonCVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:H
6.0AmazonCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-61UNIX Symbolic Link (Symlink) Following
CAPEC-27Leveraging Race Conditions via Symbolic Links
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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