How severe is CVE-2022-40855?

CVE-2022-40855 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2022-40855 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2022-40855?

CVE-2022-40855 affects Tenda W20e Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2022-40855?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2022-40855 published?

CVE-2022-40855 was published on 2022-09-23 and last updated on 2026-06-17.

CVE-2022-40855

CVE-2022-40855 is a critical-severity vulnerability in Tenda W20e Firmware with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 13% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 13% (96th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Tenda W20e Firmware
Published: 2022-09-23
Last modified: 2026-06-17

Description

Tenda W20E router V15.11.0.6 contains a stack overflow in the function formSetPortMapping with post request 'goform/setPortMapping/'. This vulnerability allows attackers to cause a Denial of Service (DoS) or Remote Code Execution (RCE) via the portMappingServer, portMappingProtocol, portMappingWan, porMappingtInternal, and portMappingExternal parameters.

Frequently asked questions

What is CVE-2022-40855?: Tenda W20E router V15.11.0.6 contains a stack overflow in the function formSetPortMapping with post request 'goform/setPortMapping/'. This vulnerability allows attackers to cause a Denial of Service (DoS) or Remote Code Execution (RCE) via the portMappingServer, portMappingProtocol, portMappingWan, porMappingtInternal, and portMappingExternal parameters.
How severe is CVE-2022-40855?: CVE-2022-40855 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2022-40855 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2022-40855?: CVE-2022-40855 affects Tenda W20e Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2022-40855?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2022-40855 published?: CVE-2022-40855 was published on 2022-09-23 and last updated on 2026-06-17.

References

https://github.com/CPSeek/Router-vuls/blob/main/Tenda/W20E/formSetPortMapping.md

Affected products (1)

cpe:2.3:o:tenda:w20e_firmware:15.11.0.6:*:*:*:*:*:*:*

More vulnerabilities in Tenda W20e Firmware

CVE-2026-24112 — Critical (CVSS 9.8): An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by specifying the…
CVE-2026-24110 — Critical (CVSS 9.8): An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may send overly long `addDhcpRules` data. When these…
CVE-2026-24115 — Critical (CVSS 9.8): An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Failure to validate the sizes of `gstup` and `gstdwn` before…
CVE-2026-24114 — Critical (CVSS 9.8): An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Failure to validate `pPortMapIndex` may lead to buffer…
CVE-2026-24113 — Critical (CVSS 9.8): An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by controlling the…
CVE-2026-24111 — Critical (CVSS 9.8): An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Attackers may exploit the vulnerability by specifying the…

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