How severe is CVE-2021-26551?

CVE-2021-26551 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-26551 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26551?

CVE-2021-26551 affects Smartfoxserver. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-26551?

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

When was CVE-2021-26551 published?

CVE-2021-26551 was published on 2021-02-09 and last updated on 2026-06-17.

CVE-2021-26551

CVE-2021-26551 is a high-severity vulnerability in Smartfoxserver with a CVSS 3.x base score of 8.8. 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-94.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.0
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-94
Affected product: Smartfoxserver
Published: 2021-02-09
Last modified: 2026-06-17

Description

An issue was discovered in SmartFoxServer 2.17.0. An attacker can execute arbitrary Python code, and bypass the javashell.py protection mechanism, by creating /config/ConsoleModuleUnlock.txt and editing /config/admin/admintool.xml to enable the Console module.

Frequently asked questions

What is CVE-2021-26551?: An issue was discovered in SmartFoxServer 2.17.0. An attacker can execute arbitrary Python code, and bypass the javashell.py protection mechanism, by creating /config/ConsoleModuleUnlock.txt and editing /config/admin/admintool.xml to enable the Console module.
How severe is CVE-2021-26551?: CVE-2021-26551 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-26551 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26551?: CVE-2021-26551 affects Smartfoxserver. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-26551?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-26551 published?: CVE-2021-26551 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:*:*:*:*:*:*:*

More vulnerabilities in Smartfoxserver

CVE-2021-26550 — Medium (CVSS 5.5): An issue was discovered in SmartFoxServer 2.17.0. Cleartext password disclosure can occur via /config/server.xml.
CVE-2021-26549 — Medium (CVSS 5.4): An XSS issue was discovered in SmartFoxServer 2.17.0. Input passed to the AdminTool console is not properly sanitized…

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