{"id":"CVE-2026-111879","kind":"vulnerability","aliases":["CVE-2026-111879"],"related":[],"title":"Perl DBI: failed DBD::DBM open leaves a lock, hanging later table opens","description":"DBI versions before 1.656 for Perl hang on a later open of a DBD::DBM table because a failed open_data does not release the table's lock.\n\nopen_data creates the table's lock file and takes an exclusive flock on it for a CREATE, before the checks that can croak: a dbm_mldbm value that is not a module name, a failing tie, or a missing data file. The croak unwinds before the table object is blessed, so nothing releases the lock, and the meta data holding the open descriptor stays cached on the database handle.\n\nThe dbm_mldbm and dbm_type values come from the DSN or the connect attributes, so a caller that chooses the serializer or the storage backend can trigger the failure.\n\nThe flock has no timeout, so a later open of that table (even through a separate database handle) blocks for as long as the handle holding the stale lock lives, in the same process or any other.","summary":"DBI before 1.656 for Perl leaks an exclusive file lock when opening a DBD::DBM table fails on a bad dbm_mldbm or dbm_type value or a missing data file. A later open of the same table then blocks indefinitely, which is a denial of service rather than code execution.","severity":"low","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["dbd-dbm","dbi","package","perl"],"not_affected_if":["no-dbd-dbm","static-dbm-config"],"how_to_check":"- Check the installed DBI version with `perl -MDBI -e 'print $DBI::VERSION'`\n- Look for DBD::DBM use in the codebase, for example `grep -r 'DBD::DBM' .`\n- Check whether dbm_mldbm or dbm_type values come from user input or DSN configuration","fix":"- Upgrade DBI to `1.656` or later\n- Until upgraded, validate dbm_mldbm and dbm_type values before connecting","status":"open","published_at":"2026-10-20T22:18:48+00:00","first_seen_at":"2026-10-23T21:57:23+00:00","triaged_at":"2026-10-25T05:04:12+00:00","updated_at":"2026-10-25T05:04:12+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-25T05:04:12Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade DBI to `1.656` or later\n- Until upgraded, validate dbm_mldbm and dbm_type values before connecting","reach":"local","title":"Perl DBI: failed DBD::DBM open leaves a lock, hanging later table opens","impact":"low","summary":"DBI before 1.656 for Perl leaks an exclusive file lock when opening a DBD::DBM table fails on a bad dbm_mldbm or dbm_type value or a missing data file. A later open of the same table then blocks indefinitely, which is a denial of service rather than code execution.","category":"package","nicknames":[],"who_cares":["perl","dbi","dbd-dbm"],"confidence":0.7,"needs_auth":"unknown","worst_case":"A later table open hangs, blocking the process or request until restart","analyst_note":"","how_to_check":"- Check the installed DBI version with `perl -MDBI -e 'print $DBI::VERSION'`\n- Look for DBD::DBM use in the codebase, for example `grep -r 'DBD::DBM' .`\n- Check whether dbm_mldbm or dbm_type values come from user input or DSN configuration","needs_analyst":false,"not_affected_if":["no-dbd-dbm","static-dbm-config"],"who_is_affected":"Applications that use Perl DBI with the DBD::DBM driver and let a caller influence the dbm_mldbm or dbm_type values through the DSN or connect attributes. Systems that only use other database drivers, or hard-code DBM settings, are not exposed to the hang.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"low"},"cost_usd":0.000638,"input_tokens":3491,"output_tokens":578,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-111879':16A,19A '-2026':15A,18A '1.656':28B,80C 'attribut':189C 'backend':200C 'bad':45B 'bless':155C 'block':65B,223C 'cach':170C 'caller':192C 'check':125C 'choos':194C 'code':75B 'come':182C 'connect':188C 'creat':107C,122C 'croak':128C,148C 'cve':14A,17A 'data':55B,97C,106C,145C,164C 'databas':173C,221C 'dbd':4A,21B,39B,90C 'dbd-dbm':20B 'dbi':2A,23B,26B,77C 'dbm':5A,22B,40B,46B,49B,91C,130C,176C,179C 'denial':70B 'descriptor':168C 'dsn':185C 'even':217C 'exclus':33B,116C 'execut':76B 'fail':3A,42B,95C,140C 'failur':204C 'file':34B,56B,112C,146C 'flock':117C,206C 'handl':174C,222C,229C 'hang':10A,83C 'hold':165C,230C 'indefinit':66B 'later':11A,58B,86C,212C 'leak':31B 'leav':7A 'live':234C 'lock':9A,35B,104C,111C,160C,233C 'long':226C 'meta':163C 'miss':54B,144C 'mldbm':47B,131C,177C 'modul':137C 'name':138C 'noth':157C 'object':153C 'open':6A,13A,37B,59B,87C,96C,105C,167C,213C 'packag':24B 'perl':1A,25B,30B,82C 'process':238C 'rather':73B 'releas':100C,158C 'separ':220C 'serial':196C 'servic':72B 'stale':232C 'stay':169C 'storag':199C 'tabl':12A,41B,63B,92C,102C,109C,152C,216C 'take':114C 'tie':141C 'timeout':209C 'trigger':202C 'type':50B,180C 'unwind':149C 'valu':51B,132C,181C 'version':78C","nicknames":[],"mitigations":[],"who_affected":"Applications that use Perl DBI with the DBD::DBM driver and let a caller influence the dbm_mldbm or dbm_type values through the DSN or connect attributes. Systems that only use other database drivers, or hard-code DBM settings, are not exposed to the hang.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T22:18:48+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-111879","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-111879","severity":null,"published_at":"2026-10-20T22:18:48+00:00","modified_at":"2026-10-22T17:21:57+00:00","first_seen_at":"2026-10-23T21:57:23+00:00","fetched_at":"2026-10-23T22:28:59+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}