CVE-2026-50636

CVE-2026-50636 is a high-severity vulnerability 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-89.

Key facts

Description

The RemoteControl API methods invite_participants and remind_participants pass a caller-supplied token-ID array into TokenDynamic::findUninvited(), which concatenates the values directly into a tid IN ('...') SQL clause without parameterization or input validation. A remote, authenticated attacker holding the tokens/update permission on a survey can inject a crafted array element to perform SQL injection. Because LimeSurvey configures its PDO connection with emulated prepared statements (emulatePrepare = true) and does not disable MySQL multi-statements, the injection supports stacked queries: the attacker can append arbitrary additional statements (INSERT/UPDATE/DELETE/DROP/CREATE) after the original SELECT. This permits both arbitrary read of any data in the database, such as administrator bcrypt password hashes (lime_users), survey response PII, session records, and global settings, all recoverable via a SLEEP() time-based blind oracle, and arbitrary write/destruction of that data, including directly overwriting the administrator password hash for immediate account takeover or dropping/truncating tables. Reads and writes extend to any schema the application's database user can access. The RemoteControl interface (RPCInterface = json/xml) must be enabled, which is not the default.

Frequently asked questions

What is CVE-2026-50636?
The RemoteControl API methods invite_participants and remind_participants pass a caller-supplied token-ID array into TokenDynamic::findUninvited(), which concatenates the values directly into a tid IN ('...') SQL clause without parameterization or input validation. A remote, authenticated attacker holding the tokens/update permission on a survey can inject a crafted array element to perform SQL injection. Because LimeSurvey configures its PDO connection with emulated prepared statements (emulatePrepare = true) and does not disable MySQL multi-statements, the injection supports stacked queries: the attacker can append arbitrary additional statements (INSERT/UPDATE/DELETE/DROP/CREATE) after the original SELECT. This permits both arbitrary read of any data in the database, such as administrator bcrypt password hashes (lime_users), survey response PII, session records, and global settings, all recoverable via a SLEEP() time-based blind oracle, and arbitrary write/destruction of that data, including directly overwriting the administrator password hash for immediate account takeover or dropping/truncating tables. Reads and writes extend to any schema the application's database user can access. The RemoteControl interface (RPCInterface = json/xml) must be enabled, which is not the default.
How severe is CVE-2026-50636?
CVE-2026-50636 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-2026-50636 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-50636?
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.
Does CVE-2026-50636 have an EU (EUVD) identifier?
Yes. CVE-2026-50636 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35770.
When was CVE-2026-50636 published?
CVE-2026-50636 was published on 2026-06-09 and last updated on 2026-06-17.

References

Other CWE-89 (SQL Injection) vulnerabilities

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