CVE Feed

    Dashboard / CVE / CVE-2026-6691

    CVE-2026-6691

    The MongoDB C Driver's Cyrus SASL integration performs unsafe string copying during username canonicalization, enabling a heap buffer overflow before any authentication or network traffic. This may be triggered by passing untrusted input in the username of a MongoDB URI with authMechanism=GSSAPI.

    Published:May 6, 2026
    Last Modified:May 7, 2026
    EPS:May 6, 2026
    EPSS Score:0.00016
    CVSS Score:7.8

    Affected Products

    Vendor
    Mongodb
    Product
    C Driver

    Exploits

    No exploit reference

    Related CVEs

    CVE-2026-88036 (CVSS 6.1) — Improper neutralization of special elements in data query logic in the GridFS component of the MongoDB C Drive…
    CVE-2026-88035 (CVSS 5.7) — A size check in the client-side authentication path of the MongoDB C Driver can wrap around, so an unusually l…
    CVE-2026-84963 (CVSS 6.3) — An incorrect numeric conversion in the JSON parsing component of the MongoDB C Driver's BSON library may cause…
    CVE-2026-84964 (CVSS 8.2) — A double free in the OpenSSL-based TLS certificate revocation checking path of the MongoDB C Driver can be rea…
    CVE-2026-84965 (CVSS 5.9) — An integer wraparound in an allocation size calculation in the BSON library's JSON parsing code can cause a bu…
    CVE-2026-84969 (CVSS 6.3) — A memory-handling error in the BSON-to-JSON conversion helpers of the MongoDB C Driver can write a small numbe…
    CVE-2026-81524 (CVSS 5.3) — A weakness in the MongoDB C Driver allows special elements in caller-supplied database and collection name com…
    CVE-2026-9100 (CVSS 6) — The MongoDB C Driver's legacy GridFS API accepts malformed file metadata from the database without adequate va…
    CVE-2026-6231 (CVSS 5.3) — The bson_validate function may return early on specific inputs and incorrectly report success. This behavior c…
    CVE-2026-4359 (CVSS 2) — A compromised third party cloud server or man-in-the-middle attacker could send a malformed HTTP response and …

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High