How severe is CVE-2021-26549?

CVE-2021-26549 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-26549 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26549?

CVE-2021-26549 affects Smartfoxserver. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-26549?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-26549 published?

CVE-2021-26549 was published on 2021-02-09 and last updated on 2026-06-17.

CVE-2021-26549

CVE-2021-26549 is a medium-severity vulnerability in Smartfoxserver with a CVSS 3.x base score of 5.4. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (68th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Smartfoxserver
Published: 2021-02-09
Last modified: 2026-06-17

Description

An XSS issue was discovered in SmartFoxServer 2.17.0. Input passed to the AdminTool console is not properly sanitized before being returned to the user. This can be exploited to execute arbitrary HTML code in a user's browser session in context of an affected site.

Frequently asked questions

What is CVE-2021-26549?: An XSS issue was discovered in SmartFoxServer 2.17.0. Input passed to the AdminTool console is not properly sanitized before being returned to the user. This can be exploited to execute arbitrary HTML code in a user's browser session in context of an affected site.
How severe is CVE-2021-26549?: CVE-2021-26549 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-26549 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26549?: CVE-2021-26549 affects Smartfoxserver. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-26549?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-26549 published?: CVE-2021-26549 was published on 2021-02-09 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:smartfoxserver:smartfoxserver:2.17.0:*:*:*:*:*:*:*

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