CVE-2026-5339: A vulnerability was detected in Tenda G103 1.0.0.5

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MEDIUM 4.7MITIGATE

CVE-2026-5339 is a medium-severity flaw (CVSS 4.7) affecting g103 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability was detected in Tenda G103 1.0.0.5. The impacted element is the function action_set_net_settings of the file gpon.lua of the component Setting Handler. Performing a manipulation of the argument authLoid/authLoidPassword/authPassword/authSerialNo/authType/oltType/usVlanId/usVlanPriority results in command injection. It is possible to initiate the attack remotely. The exploit is now public and may be used.

Why this priority

EPSS top 6%: very likely to be exploited
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	4.7 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	6.3% (top 6%)
CISA exploited list	No
Weakness	CWE-74, CWE-77
Published	2026-04-02
Last modified	2026-07-24

Publisher (CNA): VulDB · Vendor: tenda

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-02 15:16 UTCPublished CVE record published
2026-07-24 21:10 UTCUpdated Record last modified

tenda g103 firmware MITIGATE

Affected: 1.0.0.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0.0.5

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.

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-2026-5339?

g103 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-5339 being exploited?

CVE-2026-5339 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-2026-5339 affect?

CVE-2026-5339 affects g103 firmware. Severity is medium (CVSS 4.7). A vulnerability was detected in Tenda G103 1.0.0.5. The impacted element is the function action_set_net_settings of the file gpon.lua of the component Setting Handler. Performing a manipulation of the argument authLoid/authLoidPassword/auth

How urgent is CVE-2026-5339?

Priority 45/100. EPSS top 6%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2026-5338 MEDIUM 4.7 MITIGATE A security vulnerability has been detected in Tenda G103 1.0.0.5

References

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