How severe is CVE-2023-35075?

CVE-2023-35075 has a CVSS score of 3.1/10, rated LOW. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-35075?

CVE-2023-35075 affects the following packages: github.com/mattermost/mattermost/server/v8 (Go), github.com/mattermost/mattermost-server/v6 (Go). Ecosystems affected: Go.

How do I fix CVE-2023-35075?

Update github.com/mattermost/mattermost/server/v8 to 8.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-35075 is resolved across your whole dependency graph.

How do I detect CVE-2023-35075 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mattermost/mattermost/server/v8, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-35075 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2023-35075 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-35075 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-35075?

CVE-2023-35075 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 31th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-35075?

CVE-2023-35075 is classified as CWE-74 (CWE-74). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-35075 published, and has it been updated?

CVE-2023-35075 was published on November 27, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

LOW severity

CVE-2023-35075 — server

LOW

CVE-2023-35075 is a low-severity (CVSS 3.1) CWE-74 vulnerability in github.com/mattermost/mattermost/server/v8. A fix is available for github.com/mattermost/mattermost/server/v8 — see the affected versions and patch details below.

HTML injection via channel autocomplete

Also known asGHSA-jcgv-3pfq-j4hr

Published

Nov 27, 2023

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-35075.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs31th percentile — riskier than 31% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

🐹github.com/mattermost/mattermost/server/v8🐹github.com/mattermost/mattermost-server/v6

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Mattermost fails to use innerText / textContent when setting the channel name in the webapp during autocomplete, allowing an attacker to inject HTML to a victim's page by create a channel name that is valid HTML. No XSS is possible though.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/mattermost/mattermost/server/v8`	all versions	8.1.4`go get github.com/mattermost/mattermost/server/v8@v8.1.4`
🐹Go	`github.com/mattermost/mattermost-server/v6`	all versions	7.8.13`go get github.com/mattermost/mattermost-server/v6@v7.8.13`

Affected Products

1 product · 2 configurations

Application

mattermostmattermost

≥ 8.0.0 && ≤ 8.1.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mattermost/mattermost/server/v8, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/mattermost/mattermost/server/v8 to 8.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-35075 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2023-35075 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

3.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N

CWE Classification

CWE-74CWE-74

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

mattermost

7.3/10

Maintained10/10

Dependency-Update-Tool10/10

Code-Review10/10

Branch-Protection4/10

Vulnerabilities0/10

Assessed Nov 6, 2026

Timeline

Disclosed

Nov 27, 2023

Last updated

Oct 28, 2026

Identifiers

CVE-2023-35075

GHSA-jcgv-3pfq-j4hr

References

Advisorygithub.com · CVE 2023 35075.json Advisorynvd.nist.gov · CVE 2023 35075 Webmattermost.com · security updates Packagegithub.com · mattermost

Related vulnerabilities

This CVE is low severity; 8 of 8 other CVEs affecting v8 are rated as high or higher (top: high).

CVE-2026-8823CVE-2026-6046CVE-2026-7387CVE-2026-6961CVE-2026-7184CVE-2026-6689CVE-2026-6739CVE-2026-3433

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 28, 2026

CVE-2023-35075 — server

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2023-35075 in your dependencies?