CVE-2026-84964Network attack vectorHinoki check available

Client crash via OCSP request double free

Published Sep 3, 2026 · Updated Sep 3, 2026

Double free in the MongoDB C Driver 1.17.0 through 1.30.8 and 2.0.0 through 2.5.1 allows remote attackers to crash client applications. In the OpenSSL TLS certificate-revocation path, a certificate containing multiple OCSP URLs causes the same request-owned heap object to be freed twice during the handshake. Exploitation requires a TLS endpoint already trusted by the client; the demonstrated consequence is unexpected client termination, not data access or modification.

CVSS severity8.2
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
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Summary

What happened

Double free in the MongoDB C Driver 1.17.0 through 1.30.8 and 2.0.0 through 2.5.1 allows remote attackers to crash client applications. In the OpenSSL TLS certificate-revocation path, a certificate containing multiple OCSP URLs causes the same request-owned heap object to be freed twice during the handshake. Exploitation requires a TLS endpoint already trusted by the client; the demonstrated consequence is unexpected client termination, not data access or modification.

The record

CVE
CVE-2026-84964
Published
Sep 3, 2026
Updated
Sep 3, 2026
Vendor
MongoDB
Product
MongoDB C++ Driver
Classifications
CWE-415, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.17.0 <1.30.9
  2. Affected versionversion=2.0.0 <2.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MongoDB · MongoDB C++ Driverversion=1.17.0 <1.30.9; version=2.0.0 <2.5.2

Published CVSS scores

5.9MongoDBCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
8.2MongoDBCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-415Double Free
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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