CVE-2025-15255: A vulnerability was determined in Tenda W6-S 1.0.0.4(510)

This week

CRITICAL 9.8REMOTEMITIGATE

CVE-2025-15255 is a critical-severity flaw (CVSS 9.8) affecting w6-s firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability was determined in Tenda W6-S 1.0.0.4(510). This impacts an unknown function of the file /bin/httpd of the component R7websSsecurityHandler. Executing a manipulation of the argument Cookie can lead to stack-based buffer overflow. The attack may be launched remotely. The exploit has been publicly disclosed and may be utilized.

Why this priority

Critical severity
EPSS top 8%: very likely to be exploited
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.7% (top 8%)
CISA exploited list	No
Weakness	CWE-119, CWE-121
Published	2025-12-30
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: tenda

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

Am I affected?

Timeline

2025-12-30 16:15 UTCPublished CVE record published
2026-06-17 08:37 UTCUpdated Record last modified

tenda w6-s firmware MITIGATE

Affected: 1.0.0.4\(510\)

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · amule · FIXED · 3.2.0-1.fc46 · FEDORA-2026-4feb2647b0 · source

sudo dnf upgrade --advisory=FEDORA-2026-4feb2647b0

Fedora ELN · mysql9.7 · FIXED · 9.7.4-3.eln159 · FEDORA-2026-ea1c50e49b · source

sudo dnf upgrade --advisory=FEDORA-2026-ea1c50e49b

Public exploits and detection

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

Write-up: github.com/dwBruijn/CVEs/blob/main/Tenda/R7WebsSecurityHandler.md

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-2025-15255?

w6-s firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-15255 being exploited?

CVE-2025-15255 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-2025-15255 affect?

CVE-2025-15255 affects w6-s firmware. Severity is critical (CVSS 9.8). A vulnerability was determined in Tenda W6-S 1.0.0.4(510). This impacts an unknown function of the file /bin/httpd of the component R7websSsecurityHandler. Executing a manipulation of the argument Cookie can lead to stack-based buffer overf

How urgent is CVE-2025-15255?

Priority 70/100. Critical severity; EPSS top 8%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Apache HTTP Server vulnerabilities

Related CVEs

CVE-2025-28221 HIGH 7.5 MITIGATE Tenda W6_S v1.0.0.4_510 has a Buffer Overflow vulnerability in the set_local_time function, which allows remot
CVE-2025-28220 HIGH 7.5 MITIGATE Tenda W6_S v1.0.0.4_510 has a Buffer Overflow vulnerability in the setcfm function, which allows remote attack
CVE-2025-15254 MEDIUM 6.3 MITIGATE A vulnerability was found in Tenda W6-S 1.0.0.4(510)

References

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