CVE-2025-7862: A vulnerability has been found in TOTOLINK T6 4.1.5cu.748_B20211015 and classified as critical

This week

HIGH 7.3REMOTEMITIGATE

CVE-2025-7862 is a high-severity flaw (CVSS 7.3) affecting t6 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability has been found in TOTOLINK T6 4.1.5cu.748_B20211015 and classified as critical. Affected by this vulnerability is the function setTelnetCfg of the file /cgi-bin/cstecgi.cgi of the component Telnet Service. The manipulation of the argument telnet_enabled with the input 1 leads to missing authentication. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	7.3 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.2% (top 32%)
CISA exploited list	No
Weakness	CWE-287, CWE-306
Published	2025-07-20
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

2025-07-20 03:15 UTCPublished CVE record published
2026-06-17 10:05 UTCUpdated Record last modified

totolink t6 firmware MITIGATE

Affected: v4.1.5cu.748_b20211015

Fixed in: no fixed release known

Safe to downgrade to: a release before v4.1.5cu.748_b20211015

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-2025-7862?

t6 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-7862 being exploited?

CVE-2025-7862 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-2025-7862 affect?

CVE-2025-7862 affects t6 firmware. Severity is high (CVSS 7.3). A vulnerability has been found in TOTOLINK T6 4.1.5cu.748_B20211015 and classified as critical. Affected by this vulnerability is the function setTelnetCfg of the file /cgi-bin/cstecgi.cgi of the component Telnet Service. The manipulation o

How urgent is CVE-2025-7862?

Priority 53/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2025-8170 HIGH 8.8 MITIGATE A vulnerability classified as critical was found in TOTOLINK T6 4.1.5cu.748_B20211015
CVE-2025-7952 MEDIUM 6.3 MITIGATE A vulnerability classified as critical was found in TOTOLINK T6 4.1.5cu.748
CVE-2025-7913 HIGH 8.8 MITIGATE A vulnerability, which was classified as critical, was found in TOTOLINK T6 4.1.5cu.748_B20211015
CVE-2025-7912 HIGH 8.8 MITIGATE A vulnerability, which was classified as critical, has been found in TOTOLINK T6 4.1.5cu.748_B20211015
CVE-2025-7758 HIGH 8.8 MITIGATE A vulnerability, which was classified as critical, has been found in TOTOLINK T6 up to 4.1.5cu.748_B20211015

References

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