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  4. CVE 2026 120678 mongo c driver leaks the decompressed reply
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Back to active CVEs
High · CVSS 8.7CVE-2026-120678

mongo-c-driver leaks the decompressed reply buffer when an OP_COMPRESSED reply fails to parse (denial of service)CVE-2026-120678

Answer in brief

CVE-2026-120678 records a High severity (CVSS 8.7) vulnerability in mongo-c-driver leaks the decompressed reply buffer when an OP_COMPRESSED reply fails to parse (denial of service). The current sources do not mark it as known exploited. The current feed maps MongoDB/C Driver (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Nov 3, 2026Updated Nov 3, 2026Source checked Nov 3, 2026First seen by HOL Nov 3, 2026Material review Nov 3, 2026
Upstream Advisory

Key facts

Risk
High · CVSS 8.7
Exploitation
Not marked as known exploited
Affected software
1 mapped package or product
Fix availability
Not reported

Why this deserves its current priority

CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps MongoDB/C Driver (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
MongoDB/C Drivergeneric>=1.25.0 <=1.30.14 || >=2.0.0 <=2.5.7Not reported

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for MongoDB/C Driver.
  2. 2Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

  1. Published upstream

    Nov 3, 2026

    Evidence: source:cvelist:source_dates:source-dates:record
  2. Source modified

    Nov 3, 2026

    Evidence: source:cvelist:source_dates:source-dates:record
  3. First seen by HOL

    Nov 3, 2026

Sources and claim methodology

  • Source referencejira.mongodb.org
Upstream source description

A memory management flaw in the MongoDB C Driver's handling of compressed responses may cause the client library to hold on to memory that is never released. An unauthenticated party that controls the database endpoint a client application connects to may cause repeated, unbounded memory growth in that application, which may result in the application becoming unavailable. No credentials, transport security settings, or user interaction are required.

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • MongoDB C Driver 2.5.5 GridFS gap lets arotected client's passwordSame mongodb/c driver package
  • Silent element-count truncation via 32-bit bit-length overflow in packed-bit vector viewsSame mongodb/c driver package
  • MongoDB C Driver Modern GridFS mongoc_gridfs_bucket_download_to_stream() Aborts Application on Malformed GridFS MetadataSame mongodb/c driver package
  • remote abort and memory disclosure from a malformed cursor.nsSame mongodb/c driver package

Record context

Vulnerability class
Missing Auth
EPSS
Not reported
CWE IDs
CWE-401
Source
CVE List V5
Source checked
Nov 3, 2026
References
1 linked source
Open source record