CVE-2026-6691
published 2026-05-06CVE-2026-6691: The MongoDB C Driver's Cyrus SASL integration performs unsafe string copying during username canonicalization, enabling a heap buffer overflow before any…
PriorityP340high7.8CVSS 3.1
AVLACLPRNUIRSUCHIHAH
EPSS
0.13%
2.7th percentile
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.
Affected
1 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mongodb_inc | mongodb_c_driver | 2.1.0 – 2.1.2 | — |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv4.08.6HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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Bugzilla
CVE-2026-6691 mongo-c-driver: MongoDB C Driver: Heap buffer overflow via unsafe username canonicalization [epel-all]
bugzilla·2026-05-15·CVSS 8.6
CVE-2026-6691 [HIGH] CVE-2026-6691 mongo-c-driver: MongoDB C Driver: Heap buffer overflow via unsafe username canonicalization [epel-all]
CVE-2026-6691 mongo-c-driver: MongoDB C Driver: Heap buffer overflow via unsafe username canonicalization [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-6691 mongo-c-driver: MongoDB C Driver: Heap buffer overflow via unsafe username canonicalization [fedora-all]
bugzilla·2026-05-15·CVSS 8.6
CVE-2026-6691 [HIGH] CVE-2026-6691 mongo-c-driver: MongoDB C Driver: Heap buffer overflow via unsafe username canonicalization [fedora-all]
CVE-2026-6691 mongo-c-driver: MongoDB C Driver: Heap buffer overflow via unsafe username canonicalization [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-6691 MongoDB C Driver: Cyrus SASL: MongoDB C Driver: Heap buffer overflow via unsafe username canonicalization
bugzilla·2026-05-06·CVSS 8.6
CVE-2026-6691 [HIGH] CVE-2026-6691 MongoDB C Driver: Cyrus SASL: MongoDB C Driver: Heap buffer overflow via unsafe username canonicalization
CVE-2026-6691 MongoDB C Driver: Cyrus SASL: MongoDB C Driver: Heap buffer overflow via unsafe username canonicalization
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.
2026-05-06
Published