Persistent client crash loop via undersized FLE2 insert-update ciphertext in decryption path (MongoDB libmongocrypt)

CVE-2026-84971
HIGH 7.1

At a glance

Source
NVD
EPSS
EPSS 0.26 % · percentile 18 ()
State
PUBLISHED
Published
Updated
Assigner
mongodb
NVD status
Analyzed

Description

Improper handling of an unexpected value size in the decryption path of a client-side encryption library can cause a failed internal check that terminates the process using the library. A party able to place a suitably formed encrypted value where an application will decrypt it, or able to control the responses the application receives, may cause that application to stop running.

Weaknesses (CWE)

References

Scores

VersionScoreVectorScored by
CVSS 4.0HIGH 7.1CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:Nmongodb
CVSS 3.1MEDIUM 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hmongodb
CVSS 4.0HIGH 7.1CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/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:XNVD · cna@mongodb.com (Secondary)
CVSS 3.1MEDIUM 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · cna@mongodb.com (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
MongoDB · libmongocryptaffected 1.7.0 < 1.20.4

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD