CVE-2026-5103: A weakness has been identified in Totolink A3300R 17.0.0cu.557_b20221024

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MEDIUM 6.3MITIGATE

CVE-2026-5103 is a medium-severity flaw (CVSS 6.3) affecting a3300r firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A weakness has been identified in Totolink A3300R 17.0.0cu.557_b20221024. This issue affects the function setUPnPCfg of the file /cgi-bin/cstecgi.cgi. This manipulation of the argument enable causes command injection. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks.

Why this priority

EPSS top 9%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	6.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	4.1% (top 9%)
CISA exploited list	No
Weakness	CWE-74, CWE-77
Published	2026-03-30
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: totolink

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

Am I affected?

Timeline

2026-03-30 02:16 UTCPublished CVE record published
2026-06-17 10:58 UTCUpdated Record last modified

totolink a3300r firmware MITIGATE

Affected: 17.0.0cu.557_b20221024

Fixed in: no fixed release known

Safe to downgrade to: a release before 17.0.0cu.557_b20221024

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-2026-5103?

a3300r firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-5103 being exploited?

CVE-2026-5103 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-2026-5103 affect?

CVE-2026-5103 affects a3300r firmware. Severity is medium (CVSS 6.3). A weakness has been identified in Totolink A3300R 17.0.0cu.557_b20221024. This issue affects the function setUPnPCfg of the file /cgi-bin/cstecgi.cgi. This manipulation of the argument enable causes command injection. The attack is possible

How urgent is CVE-2026-5103?

Priority 50/100. EPSS top 9%: very likely to be exploited; Public exploit reference

Related CVEs

CVE-2026-5105 MEDIUM 6.3 MITIGATE A vulnerability was detected in Totolink A3300R 17.0.0cu.557_b20221024
CVE-2026-5104 MEDIUM 6.3 MITIGATE A security vulnerability has been detected in Totolink A3300R 17.0.0cu.557_b20221024
CVE-2026-5102 MEDIUM 6.3 MITIGATE A security flaw has been discovered in Totolink A3300R 17.0.0cu.557_b20221024
CVE-2026-5101 MEDIUM 6.3 MITIGATE A vulnerability was identified in Totolink A3300R 17.0.0cu.557_b20221024
CVE-2026-31181 CRITICAL 9.8 MITIGATE An issue was discovered in ToToLink A3300R firmware v17.0.0cu.557_B20221024 allowing attackers to execute arbi

References

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