CVE-2026-120811
Use-After-Free in MongoDB Server Classic Query Engine Plan Cache Leads to Information Disclosure and Denial of Service
A use-after-free issue exists in the MongoDB server’s classic query engine plan cache. Under certain query conditions, an unowned reference to data from an earlier command can be retained in cached plan statistics. After the originating memory is freed, a subsequent diagnostic command serializing those statistics can read freed heap memory, potentially returning sensitive server process memory contents to the authenticated client. Under certain heap reuse conditions, this may also cause the server to crash.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| MongoDB Server MongoDB |
≥ 9.0.0; < 9.0.7 (affected, semver) ≥ 8.3.0; < 8.3.16 (affected, semver) ≥ 8.0.0; < 8.0.37 (affected, semver) ≥ 7.0.0; < 7.0.48 (affected, semver) Other versions: unaffected |
CNA: mongodb |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 6.0 medium |
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N | CNA: mongodb |
| 3.1 / 5.9 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L | CNA: mongodb |
| 4.0 / 6.0 medium |
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:L/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 | NVD: [email protected] |
| 3.1 / 5.9 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
For agents and automation
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