{"id":"CVE-2026-120645","kind":"vulnerability","aliases":["CVE-2026-120645"],"related":[],"title":"Perl CGI: crafted form values can crash or stall scrolling_list rendering","description":"CGI versions before 5.00 for Perl allow denial of service via submitted values used as a regex for optgroup selection in scrolling_list.\n\nWhen rendering option groups, scrolling_list marks the selected options by interpolating each selected value, by default taken from the request parameters, unescaped into a substitution pattern.\n\nA client can make the request die with an invalid pattern, or tie up the process with one that backtracks heavily.","summary":"The Perl CGI module before 5.00 interpolates submitted request values unescaped into a regular expression when rendering option groups in scrolling_list. A remote client can send a value that makes the request die on an invalid pattern or consume the process with heavy backtracking, causing denial of service.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["cgi","package","perl","self-hosted"],"not_affected_if":["no-scrolling-list","static-values"],"how_to_check":"- Check the installed CGI module version with `perl -MCGI -e 'print $CGI::VERSION'`\n- Search application code for calls to `scrolling_list` that pass request parameters as selected values","fix":"- Upgrade CGI to `5.00` or later","status":"open","published_at":"2026-11-04T00:17:26+00:00","first_seen_at":"2026-11-04T00:46:17+00:00","triaged_at":"2026-11-04T00:48:10+00:00","updated_at":"2026-11-04T00:48:10+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-04T00:48:10Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade CGI to `5.00` or later\n- unknown","reach":"internet","title":"Perl CGI: crafted form values can crash or stall scrolling_list rendering","impact":"low","summary":"The Perl CGI module before 5.00 interpolates submitted request values unescaped into a regular expression when rendering option groups in scrolling_list. A remote client can send a value that makes the request die on an invalid pattern or consume the process with heavy backtracking, causing denial of service.","audience":"businesses","category":"package","nicknames":[],"who_cares":["perl","cgi","self-hosted"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"Remote requests crash or stall the Perl process, causing denial of service","analyst_note":"Confirm the fixed version and whether the default config passes request parameters to scrolling_list; check the linked patch on github.com.","how_to_check":"- Check the installed CGI module version with `perl -MCGI -e 'print $CGI::VERSION'`\n- Search application code for calls to `scrolling_list` that pass request parameters as selected values\n- unknown","plain_action":"","needs_analyst":true,"not_affected_if":["no-scrolling-list","static-values"],"who_is_affected":"Applications written in Perl that use the CGI module's scrolling_list method with values taken from user requests are exposed. Code that does not call scrolling_list, or that only passes fixed server-side values, is not affected by this description. unknown for the exact default-configuration scope.","user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"unknown"},"cost_usd":0.000699,"input_tokens":4162,"output_tokens":565,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-120645':15A,18A '-2026':14A,17A '5.00':30B,77C 'allow':80C 'backtrack':69B,143C 'caus':70B 'cgi':2A,19B,27B,74C 'client':49B,125C 'consum':64B 'craft':3A 'crash':7A 'cve':13A,16A 'default':113C 'denial':71B,81C 'die':58B,130C 'express':39B 'form':4A 'group':43B,100C 'heavi':68B 'heavili':144C 'host':24B 'interpol':31B,108C 'invalid':61B,133C 'list':11A,46B,96C,102C 'make':55B,127C 'mark':103C 'modul':28B 'one':141C 'optgroup':92C 'option':42B,99C,106C 'packag':20B 'paramet':118C 'pattern':62B,123C,134C 'perl':1A,21B,26B,79C 'process':66B,139C 'regex':90C 'regular':38B 'remot':48B 'render':12A,41B,98C 'request':33B,57B,117C,129C 'scroll':10A,45B,95C,101C 'select':93C,105C,110C 'self':23B 'self-host':22B 'send':51B 'servic':73B,83C 'stall':9A 'submit':32B,85C 'substitut':122C 'taken':114C 'tie':136C 'unescap':35B,119C 'use':87C 'valu':5A,34B,53B,86C,111C 'version':75C 'via':84C","nicknames":[],"mitigations":[],"who_affected":"Applications written in Perl that use the CGI module's scrolling_list method with values taken from user requests are exposed. Code that does not call scrolling_list, or that only passes fixed server-side values, is not affected by this description. unknown for the exact default-configuration scope.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["cgi","package","perl","selfhosted","unknown"],"campaign_type":null,"first_public_at":"2026-11-04T00:17:26+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-120645","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-120645","severity":null,"published_at":"2026-11-04T00:17:26+00:00","modified_at":"2026-11-04T00:17:26+00:00","first_seen_at":"2026-11-04T00:46:17+00:00","fetched_at":"2026-11-04T00:46:17+00:00","note":null}],"documents":[{"id":62125,"url":"https://github.com/leejo/CGI.pm/commit/824956fbb0c4eb77044ba2dc9180a30df12cb309.patch","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}