CVE-2026-6428

data from the Koha application database via the Filter URL parameter when the Criteria parameter matches /branchcode/. The vulnerable sink in sub calculate concatenates the unmodified Filter request parameter directly into a LIKE clause of the auxiliary $strsth2 statement and executes it via DBI without bound parameters: my $f = @$filters[0]; $f =~ s/\*/%/g; $strsth2 .= " AND $column LIKE '$f' "; This enables error-based SQL injection (e.g., via EXTRACTVALUE) and full read access to sensitive tables including borrowers (password hashes, 2FA secrets, PII), borrower_password_recovery, api_keys, and sessions. Proof of concept (error-based, single request): GET /cgi-bin/koha/reports/catalogue_out.pl?do_it=1&output=screen&Limit=10&Criteria=branchcode&Filter=x'+AND+EXTRACTVALUE(1,CONCAT(0x7e,VERSION(),0x7c,USER(),0x7c,DATABASE(),0x7e))--+- Cookie: CGISESSID=<LIBRARIAN_SESSION> The response body contains the DBI exception leaking the MariaDB version, database user, client IP, and database name, after which arbitrary data can be paged out using LIMIT n,1 / SUBSTRING(...). The vulnerable sink was introduced in commit 6bb77ae3e4 (2008-07-09); CVE-2015-4633 patched the same class in sibling files but did not generalise the fix to reports/catalogue_out.pl. Fixed in Koha 22.11.38, 24.11.16, 25.05.11, 25.11.05, 26.05.01, and 26.11.00 by replacing the raw concatenation with a parameterised placeholder.