How severe is CVE-2026-18709?

CVE-2026-18709 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2026-18709 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-18709?

CVE-2026-18709 primarily affects Mongodb. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-18709?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-18709 published?

CVE-2026-18709 was published on 2026-08-11 and last updated on 2026-09-16.

CVE-2026-18709

CVE-2026-18709 is a medium-severity vulnerability in Mongodb with a CVSS 3.x base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-862.

Key facts

Severity: Medium (CVSS 3.x base score 6.4)
CVSS v4: 5.9
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Mongodb
Published: 2026-08-11
Last modified: 2026-09-16

Description

An issue in MongoDB Server could allow an authenticated user with direct network access to a shard to improperly commit or abort an in-progress prepared transaction, bypassing the intended transaction coordination process. This could result in cross-shard data inconsistency, cluster clock corruption, and violation of transaction atomicity guarantees.

Frequently asked questions

What is CVE-2026-18709?: An issue in MongoDB Server could allow an authenticated user with direct network access to a shard to improperly commit or abort an in-progress prepared transaction, bypassing the intended transaction coordination process. This could result in cross-shard data inconsistency, cluster clock corruption, and violation of transaction atomicity guarantees.
How severe is CVE-2026-18709?: CVE-2026-18709 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2026-18709 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-18709?: CVE-2026-18709 primarily affects Mongodb. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-18709?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-18709 published?: CVE-2026-18709 was published on 2026-08-11 and last updated on 2026-09-16.

References

https://jira.mongodb.org/browse/SERVER-130544

Affected products (4)

cpe:2.3:a:mongodb:mongodb:*:*:*:*:*:*:*:*
cpe:2.3:a:mongodb:mongodb:9.0.0:alpha0:*:*:-:-:*:*
cpe:2.3:a:mongodb:mongodb:9.0.0:alpha1:*:*:-:-:*:*
cpe:2.3:a:mongodb:mongodb:9.1.0:alpha0:*:*:-:-:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

138.197.130.35 (ipv4-addr)
18.228.228.159 (ipv4-addr)
3.19.213.118 (ipv4-addr)