CVE-2025-1731: An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS

Q: How do I fix CVE-2025-1731?

uos: upgrade to 1.32. Exact commands for each OS are on this page.

Q: Is CVE-2025-1731 being exploited?

CVE-2025-1731 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-1731 affect?

CVE-2025-1731 affects uos. Severity is high (CVSS 7.8). An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS firmware versions from V1.20 through V1.31 could allow an authenticated local attacker with low privileges to gain access to the

Q: How urgent is CVE-2025-1731?

Priority 48/100. High severity; Public exploit reference

This month

HIGH 7.8UPGRADE

CVE-2025-1731 is a high-severity flaw (CVSS 7.8) affecting uos. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS firmware versions from V1.20 through V1.31 could allow an authenticated local attacker with low privileges to gain access to the Linux shell and escalate their privileges by crafting malicious scripts or modifying system configurations with administrator-level access through a stolen token. Modifying the system configuration is only poss

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.9% (top 39%)
CISA exploited list	No
Weakness	CWE-732
Published	2025-04-22
Last modified	2026-06-17

Publisher (CNA): Zyxel Corporation · Vendor: zyxel

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-04-22 03:15 UTCPublished CVE record published
2026-06-17 08:39 UTCUpdated Record last modified

zyxel uos UPGRADE

Affected: >= 1.20 and < 1.32

Fixed in: 1.32

Safe to downgrade to: a release before 1.20

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Zyxel USG FLEX H series uOS 1.31 - Privilege Escalation

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-1731?

uos: upgrade to 1.32. Exact commands for each OS are on this page.

Is CVE-2025-1731 being exploited?

CVE-2025-1731 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-1731 affect?

CVE-2025-1731 affects uos. Severity is high (CVSS 7.8). An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS firmware versions from V1.20 through V1.31 could allow an authenticated local attacker with low privileges to gain access to the

How urgent is CVE-2025-1731?

Priority 48/100. High severity; Public exploit reference

Software pages

PostgreSQL vulnerabilities · Zyxel vulnerabilities

Related CVEs

CVE-2025-1732 MEDIUM 6.7 MITIGATE An improper privilege management vulnerability in the recovery function of the Zyxel USG FLEX H series uOS fir

References

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