How severe is CVE-2017-18888?

CVE-2017-18888 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2017-18888 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-18888?

CVE-2017-18888 primarily affects Mattermost Mattermost Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-18888?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2017-18888 published?

CVE-2017-18888 was published on 2020-06-19 and last updated on 2026-06-17.

CVE-2017-18888

CVE-2017-18888 is a critical-severity vulnerability in Mattermost Mattermost Server with a CVSS 3.x base score of 9.8. 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-89.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (62nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-89
Affected product: Mattermost Mattermost Server
Published: 2020-06-19
Last modified: 2026-06-17

Description

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. It allows SQL injection during the fetching of multiple posts.

Frequently asked questions

What is CVE-2017-18888?: An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. It allows SQL injection during the fetching of multiple posts.
How severe is CVE-2017-18888?: CVE-2017-18888 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-18888 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-18888?: CVE-2017-18888 primarily affects Mattermost Mattermost Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-18888?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2017-18888 published?: CVE-2017-18888 was published on 2020-06-19 and last updated on 2026-06-17.

References

https://mattermost.com/security-updates/

Affected products (5)

cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc1:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc2:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc3:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:4.3.0:rc4:*:*:*:*:*:*

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