Vulnerability · Published Sep 3, 2026 · Assigned by mongodb
CVE-2026-84964Heap corruption via OCSP request double free from crafted multi-URL certificate in TLS client
Medium 5.9
In plain English
A medium-severity double free in C Driver from MongoDB. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
A double free in the OpenSSL-based TLS certificate revocation checking path of the MongoDB C Driver can be reached by a TLS endpoint that the client already trusts. During the handshake, specially formed certificate data can cause the same heap object to be released twice. An unauthenticated party acting as the trusted endpoint may cause the connecting client application to terminate unexpectedly.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | mongo-c-driver | 1.30.14-r0 | ALPINE-CVE-2026-84964 |
| Debian:12 | mongo-c-driver | no fix listed | DEBIAN-CVE-2026-84964 |
| Debian:13 | mongo-c-driver | no fix listed | DEBIAN-CVE-2026-84964 |
| Debian:14 | mongo-c-driver | 2.5.2-1 | DEBIAN-CVE-2026-84964 |
| Ubuntu:26.04:LTS | mongo-c-driver | no fix listed | UBUNTU-CVE-2026-84964 |
| Ubuntu:26.10 | mongo-c-driver | no fix listed | UBUNTU-CVE-2026-84964 |
Affected products (as reported)
Weakness: CWE-415 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H