{"id":"CVE-2026-55405","aliases":["GHSA-2mfg-cc43-9pcj"],"url":"https://o3.security/vulnerability/CVE-2026-55405","summary":"LangChain4j: SQL injection via metadata filters in langchain4j-mariadb and langchain4j-pgvector","details":"### Summary\nThe MariaDB and pgvector embedding stores build metadata-filter SQL by string-concatenating\nfilter **keys** (and, in MariaDB, string **values**) directly into the query without adequate\nescaping. A crafted metadata key in `EmbeddingSearchRequest.filter()` can break out of its SQL\ncontext and inject arbitrary SQL into the statements executed by the stores' search and\n`removeAll(Filter)` operations.\n\n### Details\n**pgvector — JSON mode (default, `COMBINED_JSON` / `COMBINED_JSONB`).** `JSONFilterMapper`\nplaces the key inside a single-quoted SQL literal (the JSON key of the `->>` operator) with no\nescaping:\n\n    (metadata->>'<key>')::text\n\nA key containing a single quote breaks out, e.g.\n`metadataKey(\"')::text IS NOT NULL OR pg_sleep(1) IS NOT NULL --\")` injects a live `pg_sleep(1)`\n(observable as a delay; exploitable for blind data extraction).\n\n**pgvector — column mode (`COLUMN_PER_KEY`).** `ColumnFilterMapper` used the key as a bare,\nunquoted, unvalidated SQL identifier (`<key>::<type>`), so a key such as `1=1 OR true --`\ninjects directly.\n\n**MariaDB — JSON mode (default).** `JSONFilterMapper` placed the key inside the JSON path literal\n`'$.<key>'` unescaped (same break-out mechanism). Additionally, `MariaDbFilterMapper.formatValue()`\nescaped `'` but not `\\`; because MariaDB treats backslash as an escape character by default, a\nstring value ending in a backslash could also break out of its literal.\n\n**MariaDB — column mode (`COLUMN_PER_KEY`).** `ColumnFilterMapper` fell back to the raw,\nunescaped key when the driver could not quote it as an identifier (e.g. a\ncharacter).\n\nThe filter key is the runtime injection surface; both stores' `search()` (including pgvector's\nHYBRID mode) and `removeAll(Filter)` are affected. Add/upsert operations a\nparameterized and not affected.\n\n### Impact\nApplications that allow attacker-influenced metadata filter keys (e.g. use\nLLM-generated filters) to reach these stores are exposed to SQL injection: blind data\nexfiltration, denial of service via sleep functions, and — through `remove\ndeletion of arbitrary rows. Applications using only hard-coded, developer-defined filter keys\nare not reachable.\n\n### Patches\nFixed in `langchain4j-mariadb` and `langchain4j-pgvector` 1.16.3-beta26:\n- JSON filter keys are escaped before being embedded in the SQL string lit\n  quotes doubled, correct for PostgreSQL `standard_conforming_strings = on`; MariaDB: backslash\n  and single quote).\n- MariaDB string values escape both `\\` and `'`.\n- Column-mode keys are validated/quoted as identifiers and rejected when u\n  concatenated as raw SQL.\n\n### Workarounds\n- Do not pass untrusted input as metadata filter keys.\n- Restrict filter keys to a known allow-list at the application layer.\n\n### References\n- pgvector: `JSONFilterMapper`, `ColumnFilterMapper`\n- MariaDB: `JSONFilterMapper`, `MariaDbFilterMapper`, `ColumnFilterMapper`","published":"2026-07-10T20:33:40.804Z","modified":"2026-08-12T16:41:19.250396Z","cvss":{"score":7.6,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L"},"epss":{"score":0.00474,"percentile":0.39641,"asOf":"2026-09-13"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"dev.langchain4j:langchain4j-mariadb","fixedVersion":"1.2.1-beta8"},{"ecosystem":"Maven","name":"dev.langchain4j:langchain4j-mariadb","fixedVersion":"1.5.1-beta11"},{"ecosystem":"Maven","name":"dev.langchain4j:langchain4j-mariadb","fixedVersion":"1.11.8-beta19"},{"ecosystem":"Maven","name":"dev.langchain4j:langchain4j-mariadb","fixedVersion":"1.16.3-beta26"},{"ecosystem":"Maven","name":"dev.langchain4j:langchain4j-pgvector","fixedVersion":"1.2.1-beta8"},{"ecosystem":"Maven","name":"dev.langchain4j:langchain4j-pgvector","fixedVersion":"1.5.1-beta11"},{"ecosystem":"Maven","name":"dev.langchain4j:langchain4j-pgvector","fixedVersion":"1.11.8-beta19"},{"ecosystem":"Maven","name":"dev.langchain4j:langchain4j-pgvector","fixedVersion":"1.16.3-beta26"}],"fix":{"url":"https://github.com/langchain4j/langchain4j/commit/13a0698bdfaf105d8aaf0367881df51358596219","label":"langchain4j/langchain4j@13a0698"},"references":[{"type":"WEB","url":"https://github.com/langchain4j/langchain4j/releases/tag/1.16.3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55405.json"},{"type":"ADVISORY","url":"https://github.com/langchain4j/langchain4j/security/advisories/GHSA-2mfg-cc43-9pcj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55405"},{"type":"FIX","url":"https://github.com/langchain4j/langchain4j/commit/13a0698bdfaf105d8aaf0367881df51358596219"},{"type":"FIX","url":"https://github.com/langchain4j/langchain4j/commit/1bc1f60aa58ef5c3c1703caf73362482480351cf"},{"type":"FIX","url":"https://github.com/langchain4j/langchain4j/commit/8805d5d128694302f1b0a2650174186862f669e7"},{"type":"FIX","url":"https://github.com/langchain4j/langchain4j/commit/ce96291dfb243c7f6753b5d65c7a77914642314f"},{"type":"FIX","url":"https://github.com/langchain4j/langchain4j/commit/f14a10ce77e4ea1b8277f67d6a81f46abd7a5bc2"},{"type":"PACKAGE","url":"https://github.com/langchain4j/langchain4j"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T16:41:19.250396Z"}}