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CVE.org (no NVD analysis yet)· CNA mongodb

CVE-2026-120955: MongoDB C Driver Modern GridFS mongoc_gridfs_bucket_download_to_stream() Aborts Application on Malformed GridFS Metadata

HighCVSS 8.7 · v4.0—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 34/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.35% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: mongo-c-driver (Debian:14) 2.5.8-1; mongo-c-driver (openSUSE:Tumbleweed) 2.5.8-1.1.

Low priority for now. Upgrade to mongo-c-driver (Debian:14) 2.5.8-1; mongo-c-driver (openSUSE:Tumbleweed) 2.5.8-1.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

The GridFS file download API in the MongoDB C Driver does not check the result of an internal operation under certain error conditions during file retrieval. This can cause the process to terminate when stream operations continue. A user who can influence file download parameters can trigger this condition, which may result in service unavailability for applications using the affected API.

Published
Nov 3, 2026
Updated
Nov 3, 2026
EPSS
0.3% · 30th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · mongodb
8.7
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-120955

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (mongodb). Independent of NVD's CPE analysis and usually ahead of it.

  • MongoDB C Driver

    • 1.25.0 and later · up to and including 1.30.14affected · semver
    • 2.0.0 and later · up to and including 2.5.7affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12mongo-c-driverfrom 0—
Debian:14mongo-c-driverbefore 2.5.8-12.5.8-1
openSUSE:Tumbleweedmongo-c-driverbefore 2.5.8-1.12.5.8-1.1

Same product

mongodb: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-93393Heap overflow via oversized decrypted TLS record sequence in Windows Secure Channel stream
    36Monitor
  • CVE-2026-120678MongoDB C Driver leaks the decompressed reply buffer when an OP_COMPRESSED reply fails to parse (denial of service)
    34Monitor
  • CVE-2026-6691MongoDB C Driver Cyrus SASL Canonicalization Buffer Overflow
    34Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-120684Nov 3, 2026 · MongoDB C Driver GridFS gap lets a shared writer recover a protected client's password
    24Monitor
  • ← EarlierCVE-2026-120954Nov 3, 2026 · Silent element-count truncation via 32-bit bit-length overflow in packed-bit vector views
    25Monitor
  • Later →CVE-2026-120956Nov 3, 2026 · remote abort and memory disclosure from a malformed cursor.ns
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:mongo-c-driver2.5.8-1 · Debian:14Package registry (OSV)
opensuse:mongo-c-driver2.5.8-1.1 · openSUSE:TumbleweedPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recorded+3 d
  3. TodayNov 12, 2026+9 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓
  2. SSVC exploitation— → none
  3. Exploit maturity— → none

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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