{"id":"CVE-2026-126196","kind":"vulnerability","aliases":["CVE-2026-126196"],"related":[],"title":"pgEdge Postgres MCP Server: read-only mode can be bypassed to write data","description":"pgEdge Postgres MCP Server enables SQL queries against PostgreSQL databases through Model Context Protocol compatible clients. Prior to 1.1.0, query_database on a read_only connection could send unrecognized statements through pgx Exec without bind parameters, selecting PostgreSQL's simple query protocol and allowing multiple semicolon-separated statements in one request. A caller could combine transaction or session state changes with database writes, and pooled session state could leave later calls writable, when the connecting role held write privileges. The flaw affected deployments relying on read_only as a safety boundary, could compromise integrity and availability, and did not add confidentiality impact beyond the reads already permitted by the connection. This issue is fixed in 1.1.0.","summary":"The pgEdge Postgres MCP Server lets MCP clients run SQL against PostgreSQL. Before 1.1.0, statements sent to query_database on a read-only connection could chain multiple semicolon-separated statements, letting a caller change data or session state when the database role had write privileges.","severity":"high","cvss":8.1,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"pgEdge Postgres MCP Server","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["ai-tooling","mcp","pgedge","postgresql"],"not_affected_if":["read-only-database-role","version-1.1.0-or-later"],"how_to_check":"- Check the installed pgEdge Postgres MCP Server version; anything before `1.1.0` is affected.\n- Check whether connections rely on `read_only` as the write-protection boundary and whether the connecting database role has write privileges.","fix":"- pgEdge Postgres MCP Server: upgrade to `1.1.0`.","status":"open","published_at":"2026-11-12T18:17:24+00:00","first_seen_at":"2026-11-12T18:40:38+00:00","triaged_at":"2026-11-12T18:42:45+00:00","updated_at":"2026-11-12T18:42:45+00:00","category":"ai-tooling","confidence":0.7,"triage":{"at":"2026-11-12T18:42:45Z","model":"claude-haiku-5-5","output":{"fix":"- pgEdge Postgres MCP Server: upgrade to `1.1.0`.","reach":"network","title":"pgEdge Postgres MCP Server: read-only mode can be bypassed to write data","impact":"high","summary":"The pgEdge Postgres MCP Server lets MCP clients run SQL against PostgreSQL. Before 1.1.0, statements sent to query_database on a read-only connection could chain multiple semicolon-separated statements, letting a caller change data or session state when the database role had write privileges.","audience":"businesses","category":"ai-tooling","nicknames":[],"who_cares":["mcp","postgresql","pgedge"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"Database rows changed by a caller on a read-only connection","analyst_note":"","how_to_check":"- Check the installed pgEdge Postgres MCP Server version; anything before `1.1.0` is affected.\n- Check whether connections rely on `read_only` as the write-protection boundary and whether the connecting database role has write privileges.","plain_action":"","product_name":"pgEdge Postgres MCP Server","needs_analyst":false,"not_affected_if":["version-1.1.0-or-later","read-only-database-role"],"who_is_affected":"Teams running the pgEdge Postgres MCP Server before 1.1.0 that treat the read-only connection setting as their safety boundary, and whose database role can write. Deployments where the role is read-only at the database level, or that do not expose the server to MCP clients, are not exposed to the write bypass.","user_interaction":"no","product_ecosystem":"vendor","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000772,"input_tokens":4746,"output_tokens":594,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-126196':17A,20A '-2026':16A,19A '1.1.0':44B,96C,194C 'add':178C 'affect':160C 'ai':26B 'ai-tool':25B 'allow':121C 'alreadi':184C 'avail':174C 'beyond':181C 'bind':112C 'boundari':169C 'bypass':11A 'call':149C 'caller':65B,131C 'chain':57B 'chang':66B,138C 'client':38B,93C 'combin':133C 'compat':92C 'compromis':171C 'confidenti':179C 'connect':55B,103C,153C,188C 'context':90C 'could':56B,104C,132C,146C,170C 'cve':15A,18A 'data':14A,67B 'databas':49B,73B,87C,98C,140C 'deploy':161C 'enabl':82C 'exec':110C 'fix':192C 'flaw':159C 'held':155C 'impact':180C 'integr':172C 'issu':190C 'later':148C 'leav':147C 'let':36B,63B 'mcp':3A,23A,28B,34B,37B,80C 'mode':8A 'model':89C 'multipl':58B,122C 'one':128C 'paramet':113C 'permit':185C 'pgedg':1A,29B,32B,78C 'pgedge':21A 'pgx':109C 'pool':143C 'postgr':2A,33B,79C 'postgres':22A 'postgresql':30B,42B,86C,115C 'prior':94C 'privileg':77B,157C 'protocol':91C,119C 'queri':48B,84C,97C,118C 'read':6A,53B,101C,164C,183C 'read-on':5A,52B 'reli':162C 'request':129C 'role':74B,154C 'run':39B 'safeti':168C 'select':114C 'semicolon':60B,124C 'semicolon-separ':59B,123C 'send':105C 'sent':46B 'separ':61B,125C 'server':4A,24A,35B,81C 'session':69B,136C,144C 'simpl':117C 'sql':40B,83C 'state':70B,137C,145C 'statement':45B,62B,107C,126C 'tool':27B 'transact':134C 'unrecogn':106C 'without':111C 'writabl':150C 'write':13A,76B,141C,156C","nicknames":[],"mitigations":[],"who_affected":"Teams running the pgEdge Postgres MCP Server before 1.1.0 that treat the read-only connection setting as their safety boundary, and whose database role can write. Deployments where the role is read-only at the database level, or that do not expose the server to MCP clients, are not exposed to the write bypass.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":["pgedgepostgresmcpserver","postgresmcpserver"],"ptokens":["mcp","pgedge","postgres","server"],"labels":["aitooling","high","mcp","pgedge","postgresql","vendor"],"campaign_type":null,"search_a":"'-126196':17A,20A '-2026':16A,19A 'bypass':11A 'cve':15A,18A 'data':14A 'mcp':3A,23A 'mode':8A 'pgedg':1A 'pgedge':21A 'postgr':2A 'postgres':22A 'read':6A 'read-on':5A 'server':4A,24A 'write':13A","search_b":"'1.1.0':44B 'ai':26B 'ai-tool':25B 'caller':65B 'chain':57B 'chang':66B 'client':38B 'connect':55B 'could':56B 'data':67B 'databas':49B,73B 'let':36B,63B 'mcp':28B,34B,37B 'multipl':58B 'pgedg':29B,32B 'postgr':33B 'postgresql':30B,42B 'privileg':77B 'queri':48B 'read':53B 'read-on':52B 'role':74B 'run':39B 'semicolon':60B 'semicolon-separ':59B 'sent':46B 'separ':61B 'server':35B 'session':69B 'sql':40B 'state':70B 'statement':45B,62B 'tool':27B 'write':76B","search_c":"'1.1.0':96C,194C 'add':178C 'affect':160C 'allow':121C 'alreadi':184C 'avail':174C 'beyond':181C 'bind':112C 'boundari':169C 'call':149C 'caller':131C 'chang':138C 'client':93C 'combin':133C 'compat':92C 'compromis':171C 'confidenti':179C 'connect':103C,153C,188C 'context':90C 'could':104C,132C,146C,170C 'databas':87C,98C,140C 'deploy':161C 'enabl':82C 'exec':110C 'fix':192C 'flaw':159C 'held':155C 'impact':180C 'integr':172C 'issu':190C 'later':148C 'leav':147C 'mcp':80C 'model':89C 'multipl':122C 'one':128C 'paramet':113C 'permit':185C 'pgedg':78C 'pgx':109C 'pool':143C 'postgr':79C 'postgresql':86C,115C 'prior':94C 'privileg':157C 'protocol':91C,119C 'queri':84C,97C,118C 'read':101C,164C,183C 'reli':162C 'request':129C 'role':154C 'safeti':168C 'select':114C 'semicolon':124C 'semicolon-separ':123C 'send':105C 'separ':125C 'server':81C 'session':136C,144C 'simpl':117C 'sql':83C 'state':137C,145C 'statement':107C,126C 'transact':134C 'unrecogn':106C 'without':111C 'writabl':150C 'write':141C,156C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-09-03T12:42:40+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-126196","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126196","severity":null,"published_at":"2026-11-12T18:17:24+00:00","modified_at":"2026-11-12T18:17:24+00:00","first_seen_at":"2026-11-12T18:40:38+00:00","fetched_at":"2026-11-12T18:40:38+00:00","note":null}],"documents":[{"id":137478,"url":"https://github.com/pgEdge/pgedge-postgres-mcp/commit/b5b929305de7a22cd6ed7de8ae1be2ac90ca0868","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":116898,"url":"https://github.com/pgEdge/pgedge-postgres-mcp/releases/tag/v1.1.0","title":"Release notes: github.com","kind":"release","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release notes: github.com"},{"id":137480,"url":"https://github.com/pgEdge/pgedge-postgres-mcp/security/advisories/GHSA-j7mp-839j-jrm7","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-09-03T12:42:40+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}