How severe is CVE-2021-26810?

CVE-2021-26810 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-2021-26810 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26810?

CVE-2021-26810 affects Dlink Dir-816 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-26810?

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-2021-26810 published?

CVE-2021-26810 was published on 2021-03-30 and last updated on 2026-06-17.

CVE-2021-26810

CVE-2021-26810 is a critical-severity vulnerability in Dlink Dir-816 Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Dlink Dir-816 Firmware
Published: 2021-03-30
Last modified: 2026-06-17

Description

D-link DIR-816 A2 v1.10 is affected by a remote code injection vulnerability. An HTTP request parameter can be used in command string construction in the handler function of the /goform/dir_setWanWifi, which can lead to command injection via shell metacharacters in the statuscheckpppoeuser parameter.

Frequently asked questions

What is CVE-2021-26810?: D-link DIR-816 A2 v1.10 is affected by a remote code injection vulnerability. An HTTP request parameter can be used in command string construction in the handler function of the /goform/dir_setWanWifi, which can lead to command injection via shell metacharacters in the statuscheckpppoeuser parameter.
How severe is CVE-2021-26810?: CVE-2021-26810 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-2021-26810 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26810?: CVE-2021-26810 affects Dlink Dir-816 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-26810?: 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-2021-26810 published?: CVE-2021-26810 was published on 2021-03-30 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:dlink:dir-816_firmware:1.10b05:*:*:*:*:*:*:*

More vulnerabilities in Dlink Dir-816 Firmware

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