How severe is CVE-2023-30538?

CVE-2023-30538 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2023-30538 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-30538?

CVE-2023-30538 primarily affects Discourse. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-30538?

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

When was CVE-2023-30538 published?

CVE-2023-30538 was published on 2023-04-18 and last updated on 2026-06-17.

CVE-2023-30538

CVE-2023-30538 is a medium-severity vulnerability in Discourse with a CVSS 3.x base score of 5.4. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Discourse
Published: 2023-04-18
Last modified: 2026-06-17

Description

Discourse is an open source platform for community discussion. Due to the improper sanitization of SVG files, an attacker can execute arbitrary JavaScript on the users’ browsers by uploading a crafted SVG file. This issue is patched in the latest stable and tests-passed versions of Discourse. Users are advised to upgrade. For users unable to upgrade there are two possible workarounds: enable CDN handing of uploads (and ensure the CDN sanitizes SVG files) or disable SVG file uploads by ensuring that the `authorized extensions` site setting does not include `svg` (or reset that setting to the default, by default Discourse doesn't enable SVG uploads by users).

Frequently asked questions

What is CVE-2023-30538?: Discourse is an open source platform for community discussion. Due to the improper sanitization of SVG files, an attacker can execute arbitrary JavaScript on the users’ browsers by uploading a crafted SVG file. This issue is patched in the latest stable and tests-passed versions of Discourse. Users are advised to upgrade. For users unable to upgrade there are two possible workarounds: enable CDN handing of uploads (and ensure the CDN sanitizes SVG files) or disable SVG file uploads by ensuring that the `authorized extensions` site setting does not include `svg` (or reset that setting to the default, by default Discourse doesn't enable SVG uploads by users).
How severe is CVE-2023-30538?: CVE-2023-30538 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2023-30538 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-30538?: CVE-2023-30538 primarily affects Discourse. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-30538?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-30538 published?: CVE-2023-30538 was published on 2023-04-18 and last updated on 2026-06-17.

References

https://github.com/discourse/discourse/security/advisories/GHSA-w5mv-4pjf-xj43

Affected products (5)

cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*
cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:*
cpe:2.3:a:discourse:discourse:3.1.0:beta1:*:*:beta:*:*:*
cpe:2.3:a:discourse:discourse:3.1.0:beta2:*:*:beta:*:*:*
cpe:2.3:a:discourse:discourse:3.1.0:beta3:*:*:beta:*:*:*

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