CVE-2026-105107 in Koha
Summary
by MITRE • 10/14/2026
Koha is vulnerable to SQL injection in the Most-circulated items report. The reports/cat_issues_top.pl script (sub calculate) concatenates the user-controlled Criteria, Filter, and Limit request parameters directly into dynamic SQL. Criteria is only prefix-normalized and never validated against an allow-list, so it is inserted verbatim into identifier positions (SELECT DISTINCTROW, GROUP BY, ORDER BY, and the main calculation query). Filter values are concatenated raw into single-quoted LIKE, BETWEEN, and comparison fragments. Limit is appended raw to a LIMIT clause. An authenticated staff user with the reports module permission (not requiring superlibrarian) can inject arbitrary SQL and read any table reachable by the Koha database user, including borrowers (userid and bcrypt password hashes, two-factor secrets, personal data), api_keys, and sessions. The issue is fixed in Koha 24.11.19, 25.05.14, 25.11.08, and 26.05.03, and in the 26.11 development branch. This is the unpatched twin of reports/bor_issues_top.pl (CVE-2026-70372).
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Analysis
by VulDB Data Team • 10/14/2026
The Koha Integrated Library System contains a critical SQL injection vulnerability within its reporting module, specifically affecting the Most-circulated items report functionality. This security flaw resides in the Perl script reports/cat_issues_top.pl, particularly within the calculate subroutine which handles dynamic query construction. The root cause of this vulnerability is the direct concatenation of user-controlled input parameters into SQL statements without adequate sanitization or parameterization. Specifically, three distinct request parameters are exploited: Criteria, Filter, and Limit. These inputs are processed in a manner that allows an attacker to inject arbitrary Structured Query Language commands directly into the database engine, bypassing intended application logic and data access controls.
The vulnerability manifests through multiple injection vectors within the same script. The Criteria parameter is subjected only to prefix normalization but lacks validation against an allow-list of permitted column names or identifiers. Consequently, this value is inserted verbatim into critical identifier positions such as SELECT DISTINCTROW, GROUP BY, ORDER BY clauses, and the main calculation query structure. Because SQL identifiers cannot be safely handled by standard prepared statement placeholders in many database engines, this design flaw allows for structural manipulation of the query itself. Furthermore, Filter values are concatenated raw into single-quoted LIKE, BETWEEN, and comparison fragments, enabling classic string-based injection techniques that can alter logical conditions or extract data via error-based or blind extraction methods. The Limit parameter is also appended directly to the LIMIT clause without integer validation, potentially allowing for syntax errors or further exploitation depending on the database backend's handling of malformed limit values.
The operational impact of this vulnerability is severe due to its low barrier to entry and high potential reach. Authentication as a staff user with permission to access the reports module is sufficient to exploit this flaw; notably, superlibrarian privileges are not required, expanding the attack surface to include lower-level library personnel who may have legitimate but limited system access. Once exploited, an attacker can execute arbitrary SQL commands against the Koha database backend. This capability allows for the exfiltration of any data accessible by the database user account running the application. Sensitive information at risk includes borrower records containing unique identifiers and bcrypt password hashes, which could facilitate offline cracking attacks if credentials are reused elsewhere. Additionally, two-factor authentication secrets stored in the system can be extracted, effectively neutralizing multi-factor security controls for targeted accounts. The attacker may also access api_keys used for programmatic integration with other systems and active session tokens, potentially leading to full account takeover or unauthorized API usage across connected services.
From a classification perspective, this vulnerability aligns closely with CWE-89 Improper Neutralization of Special Elements used in an SQL Command, commonly known as SQL Injection. The specific exploitation technique involving identifier injection via the Criteria parameter also relates to CWE-564 SQL Injection: Hibernate and JPA, although applicable broadly to dynamic query construction flaws where identifiers are not whitelisted. In terms of adversary behavior mapping under MITRE ATT&CK, this vulnerability facilitates Data from Information Repositories (T1005) through direct database queries and potentially Account Manipulation (T1098) if session or API keys are harvested for persistent access. The lack of input validation on structural query components represents a fundamental failure in secure coding practices regarding dynamic SQL generation.
Mitigation strategies must prioritize immediate patching as the primary defense vector. Koha has addressed this issue in versions 24.11.19, 25.05.14, 25.11.08, and 26.05.03, with fixes also available in the 26.11 development branch. Organizations running unpatched instances should upgrade to one of these secure versions immediately. For environments where immediate patching is not feasible due to operational constraints, temporary mitigations include restricting access to the reports module exclusively to high-privilege accounts while monitoring for anomalous query patterns in database logs. Implementing a Web Application Firewall with rules tuned to detect SQL injection payloads in report parameters may provide partial protection against automated exploitation attempts, though it should never be considered a substitute for code-level remediation. Additionally, ensuring that the Koha database user operates under the principle of least privilege can limit the blast radius if an injection is successfully executed, by restricting access to only those tables strictly necessary for core library operations and removing direct read permissions on sensitive metadata or authentication storage tables where possible. This vulnerability serves as a reminder that even internal-facing modules with moderate permission requirements require rigorous input validation and parameterized query execution to prevent data breaches.