How severe is CVE-2023-26040?

CVE-2023-26040 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.

Is CVE-2023-26040 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-26040?

CVE-2023-26040 affects Discourse. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-26040?

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

When was CVE-2023-26040 published?

CVE-2023-26040 was published on 2023-03-17 and last updated on 2026-06-17.

CVE-2023-26040

CVE-2023-26040 is a medium-severity vulnerability in Discourse with a CVSS 3.x base score of 6.5. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Discourse
Published: 2023-03-17
Last modified: 2026-06-17

Description

Discourse is an open-source discussion platform. Between versions 3.1.0.beta2 and 3.1.0.beta3 of the `tests-passed` branch, editing or responding to a chat message containing malicious content could lead to a cross-site scripting attack. This issue is patched in version 3.1.0.beta3 of the `tests-passed` branch. There are no known workarounds.

Frequently asked questions

What is CVE-2023-26040?: Discourse is an open-source discussion platform. Between versions 3.1.0.beta2 and 3.1.0.beta3 of the `tests-passed` branch, editing or responding to a chat message containing malicious content could lead to a cross-site scripting attack. This issue is patched in version 3.1.0.beta3 of the `tests-passed` branch. There are no known workarounds.
How severe is CVE-2023-26040?: CVE-2023-26040 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2023-26040 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-26040?: CVE-2023-26040 affects Discourse. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-26040?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-26040 published?: CVE-2023-26040 was published on 2023-03-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:discourse:discourse:3.1.0:beta2:*:*:beta:*:*:*

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