CVE-2026-84971

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Source
https://cve.org/CVERecord?id=CVE-2026-84971
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84971.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-84971
Downstream
Published
2026-09-03T14:57:35Z
Modified
2026-09-19T03:47:24Z
Severity
  • 7.1 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
Summary
Persistent client crash loop via undersized FLE2 insert-update ciphertext in decryption path
Details

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.

Database specific 
{
    "cna_assigner": "mongodb",
    "cwe_ids": [
        "CWE-617"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84971.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "introduced": "1.7.0"
                },
                {
                    "fixed": "1.20.4"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ]
}
References

Affected packages

Git / github.com/mongodb/libmongocrypt

Affected ranges

Type
GIT
Repo
https://github.com/mongodb/libmongocrypt
Events
Introduced
76a17191ae96c24c1b984a763f4a2b8fe5935ce8
Fixed
ab45a792fd995db28b6fde3e730edf6a7a90fbf4
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:mongodb:libmongocrypt:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "1.7.0"
        },
        {
            "fixed": "1.20.4"
        }
    ],
    "source": "CPE_RANGE"
}

Affected versions

1.*
1.10.0b0
1.10.0b1
1.20.0
1.20.1
1.20.2
1.20.3
csharp-v1.*
csharp-v1.10.0
csharp-v1.11.0
csharp-v1.8.1
csharp-v1.8.2
csharp-v1.9.0
java-1.*
java-1.11.0
node-v6.*
node-v6.0.0
node-v6.0.0-alpha.2
node-v6.0.0-alpha.3
node-v6.0.1
pymongocrypt-1.*
pymongocrypt-1.10.0
pymongocrypt-1.10.1
pymongocrypt-1.11.0
pymongocrypt-1.12.0
pymongocrypt-1.12.1
pymongocrypt-1.12.2
pymongocrypt-1.12.2rc1
pymongocrypt-1.12.2rc2
pymongocrypt-1.12.2rc4
pymongocrypt-1.13.0
pymongocrypt-1.14.0
pymongocrypt-1.14.1
pymongocrypt-1.15.0
pymongocrypt-1.15.1
pymongocrypt-1.16.0
pymongocrypt-1.17.0
pymongocrypt-1.18.0
pymongocrypt-1.18.0.dev0
pymongocrypt-1.18.1
pymongocrypt-1.2.2rc0
pymongocrypt-1.7.0
pymongocrypt-1.8.0
pymongocrypt-1.9.0
pymongocrypt-1.9.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84971.json"