CVE-2026-96746
Heap buffer overflow via mid-scan command list growth in client topology monitoring
An out-of-bounds write in the connection-monitoring logic of the MongoDB C Driver may allow an unauthenticated party who controls name resolution and the responses of the hosts named in a client's connection string to write beyond the end of a heap buffer. This may cause the application using the driver to terminate unexpectedly.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
8.3
Heap buffer overflow via mid-scan command list growth in client topology monitoring
An out-of-bounds write in the connection-monitoring logic of the MongoDB C Driver may allow an unauthenticated party who controls name resolution and the responses of the hosts named in a client's connection string to write beyond the end of a heap buffer. This may cause the application using the driver to terminate unexpectedly.
- Record
CVE-2026-96746- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
EUVDEUVD-2026-86263
8.3
An out-of-bounds write in the connection-monitoring logic of the MongoDB C Driver may allow an unauthenticated party who controls name resolution and the responses of the hosts named in a client's connection string to write beyond the end of a heap buffer. This may cause the application using the driver to terminate unexpectedly.
- Record
EUVD-2026-86263- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
NVD
8.3
An out-of-bounds write in the connection-monitoring logic of the MongoDB C Driver may allow an unauthenticated party who controls name resolution and the responses of the hosts named in a client's connection string to write beyond the end of a heap buffer. This may cause the application using the driver to terminate unexpectedly.
- Record
CVE-2026-96746- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/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 - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
8.3
Heap buffer overflow via mid-scan command list growth in client topology monitoring
An out-of-bounds write in the connection-monitoring logic of the MongoDB C Driver may allow an unauthenticated party who controls name resolution and the responses of the hosts named in a client's connection string to write beyond the end of a heap buffer. This may cause the application using the driver to terminate unexpectedly.
- Record
CVE-2026-96746- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-787
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-96746
8.3
An out-of-bounds write in the connection-monitoring logic of the MongoDB C Driver may allow an unauthenticated party who controls name resolution and the responses of the hosts named in a client's connection string to write beyond the end of a heap buffer. This may cause the application using the driver to terminate unexpectedly.
- Record
DEBIAN-CVE-2026-96746- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/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 - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-96746
8.3
An out-of-bounds write in the connection-monitoring logic of the MongoDB C Driver may allow an unauthenticated party who controls name resolution and the responses of the hosts named in a client's connection string to write beyond the end of a heap buffer. This may cause the application using the driver to terminate unexpectedly.
- Record
UBUNTU-CVE-2026-96746- CVSS 4.0
- 8.3 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mongo-c-driverDebian:12 |
All versions, plus listed versions 1.23.1-11.23.1-1+deb12u11.23.1-1+deb12u21.23.1-1+deb12u31.24.1-1 Show 45 moreShow less1.24.2-11.24.3-11.24.4-11.25.0-11.25.1-11.25.2-11.25.4-11.25.4-1.1~exp11.26.0-11.26.0-1.11.26.0-1.1~exp11.26.1-11.26.2-11.27.0-11.27.1-11.27.2-11.27.3-11.27.4-11.27.5-11.27.6-11.28.0-11.28.1-11.29.0-11.29.1-11.29.2-11.30.0-11.30.1-11.30.2-11.30.3-11.30.4-12.0.2-12.1.0-12.1.1-12.1.2-12.2.0-12.2.1-12.2.2-12.2.3-12.2.4-12.3.0-12.3.1-12.3.2-12.3.3-12.4.0-12.5.0-1 |
None known |
mongo-c-driverDebian:13 |
All versions, plus listed versions 1.30.4-11.30.4-1+deb13u11.30.4-1+deb13u21.30.4-1+deb13u32.0.2-1 Show 18 moreShow less2.1.0-12.1.1-12.1.2-12.2.0-12.2.1-12.2.2-12.2.3-12.2.4-12.3.0-12.3.1-12.3.2-12.3.3-12.4.0-12.5.0-12.5.1-12.5.2-12.5.3-12.5.5-1 |
None known |
mongo-c-driverDebian:14 |
before 2.5.5-1, plus listed versions 1.30.4-12.0.2-12.1.0-12.1.1-12.1.2-1 Show 14 moreShow less2.2.0-12.2.1-12.2.2-12.2.3-12.2.4-12.3.0-12.3.1-12.3.2-12.3.3-12.4.0-12.5.0-12.5.1-12.5.2-12.5.3-1 |
2.5.5-1 |
pymongoUbuntu:14.04:LTS |
All versions, plus listed versions 2.6-12.6.2-12.6.3-12.6.3-1build1 |
None known |
pymongoUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 3.0.3-13.2-13.2-1build13.2-1ubuntu0.1~esm1 |
None known |
pymongoUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 3.4.0-1build23.6.1+dfsg1-13.6.1+dfsg1-1ubuntu0.1~esm1 |
None known |
pymongoUbuntu:20.04:LTS |
All versions, plus listed versions 3.7.1-1.13.7.1-1.1build13.10.1-0ubuntu23.10.1-0ubuntu2.1 |
None known |
pymongoUbuntu:22.04:LTS |
All versions, plus listed versions 3.11.0-1build23.11.0-1build33.11.0-1build43.11.0-1ubuntu0.22.04.1 |
None known |
pymongoUbuntu:24.04:LTS |
All versions, plus listed versions 3.11.0-1build63.11.0-1build73.11.0-1build83.11.0-1ubuntu0.24.04.1 |
None known |
pymongoUbuntu:26.10 |
All versions, plus listed versions 4.16.0-1build14.17.0-1 |
None known |
pymongoUbuntu:26.04:LTS |
All versions, plus listed versions 4.10.1-64.15.3-14.15.3-24.15.5-14.16.0-14.16.0-1build1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-96746 is a high vulnerability (CVSS 8.3) in Mongodb C Driver, published September 24, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.40%, the 34th percentile. Fixed in mongo-c-driver 2.5.5-1.
References
github.com/mongodb/mongo-c-driver/security/advisories/GHSA-frjf-h5jg-4v46
github.com/mongodb/mongo-c-driver/releases/tag/1.30.12
github.com/mongodb/mongo-c-driver/releases/tag/2.5.5
github.com/CVEProject/cvelistV5/tree/main/cves/2026/96xxx/CVE-2026-96746.json
nvd.nist.gov/vuln/detail/CVE-2026-96746
security-tracker.debian.org/tracker/CVE-2026-96746
ubuntu.com/security/CVE-2026-96746
cve.org/CVERecord?id=CVE-2026-96746
Left out here: 4 versions. The JSON record has them.