PostgreSQL libpq lo_* functions let server superuser overwrite client stack memory_CVE-2026-6477

{
    "lastseen": "",
    "description": "Use of inherently dangerous function PQfn(..., result_is_int=0, ...) in PostgreSQL libpq lo_export(), lo_read(), lo_lseek64(), and lo_tell64() functions allows the server superuser to overwrite a client stack buffer with an arbitrarily-large response.  Like gets(), PQfn(..., result_is_int=0, ...) stores arbitrary-length, server-determined data into a buffer of unspecified size.  Because both the \\lo_export command in psql and pg_dump call lo_read(), the server superuser can overwrite pg_dump or psql stack memory.  Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.",
    "published": "2026-05-14T13:00:12.497Z",
    "modified": "2026-05-14T13:00:12.497Z",
    "type": "cve",
    "title": "PostgreSQL libpq lo_* functions let server superuser overwrite client stack memory",
    "source": "PostgreSQL",
    "references": "https://www.postgresql.org/support/security/CVE-2026-6477/",
    "id": "CVE-2026-6477",
    "bulletinFamily": "",
    "cwe": [
        "CWE-242"
    ],
    "cvelist": null,
    "sourceData": "n/a PostgreSQL 18\nn/a PostgreSQL 17\nn/a PostgreSQL 16\nn/a PostgreSQL 15\nn/a PostgreSQL 0",
    "sourceHref": "",
    "cvss": {
        "score": 8.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "PostgreSQL",
    "version": "18",
    "vendor": "n/a",
    "ai_description": "Server superuser can overwrite client stack buffer with an arbitrarily-large response in PostgreSQL libpq lo_export(), lo_read(), lo_lseek64(), and lo_tell64() functions",
    "ai_severity": "High",
    "ai_vendor": "PostgreSQL Global Development Group",
    "ai_product": "PostgreSQL",
    "ai_version": "18.4, 17.10, 16.14, 15.18, 14.23",
    "ai_score": 8.8
}