Public vulnerability disclosure

CVE-2026-120813

Plaintext storage of encrypted fields via duplicate keys in client-side encryption schema parsing

publishedCWE-436

An issue in MongoDB Server's client-side field-level encryption (CSFLE) schema processing component allows encryption metadata to be silently dropped during schema parsing under certain conditions. A party who can deliver a specially crafted schema to a user's CSFLE client may cause sensitive data intended for encryption to be stored in plaintext, bypassing confidentiality protections. Exploitation requires the ability to deliver the malicious schema to the user's client, such as through a man-in-the-middle position or an untrusted server.

Technical severity8.2 highCVSS 4.0 · CNA: mongodb
Published2026-11-10Source updated 2026-11-13
Collected2026-11-133 attributed sources

Fixes and workarounds

No remediation reported in collected sources.

Missing remediation information is not evidence that no patch exists.

Affected products and versions

Affected products, source version ranges and reporting authorities
ProductVersionsAuthority
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

CVSS scores, vectors and reporting authorities
Version / scoreVectorAuthority
4.0 / 8.2
high
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NCNA: mongodb
3.1 / 5.9
medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NCNA: mongodb
4.0 / 8.2
high
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/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:XNVD: [email protected]
3.1 / 5.9
medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NNVD: [email protected]

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

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