How severe is CVE-2021-41271?

CVE-2021-41271 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.

Is CVE-2021-41271 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-41271?

CVE-2021-41271 primarily affects Discourse. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-41271?

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

When was CVE-2021-41271 published?

CVE-2021-41271 was published on 2021-11-15 and last updated on 2026-06-17.

CVE-2021-41271

CVE-2021-41271 is a medium-severity vulnerability in Discourse with a CVSS 3.x base score of 4.8. 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
CVSS v2: 5.0
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Discourse
Published: 2021-11-15
Last modified: 2026-06-17

Description

Discourse is a platform for community discussion. In affected versions a maliciously crafted request could cause an error response to be cached by intermediate proxies. This could cause a loss of confidentiality for some content. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.

Frequently asked questions

What is CVE-2021-41271?: Discourse is a platform for community discussion. In affected versions a maliciously crafted request could cause an error response to be cached by intermediate proxies. This could cause a loss of confidentiality for some content. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.
How severe is CVE-2021-41271?: CVE-2021-41271 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.
Is CVE-2021-41271 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-41271?: CVE-2021-41271 primarily affects Discourse. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-41271?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-41271 published?: CVE-2021-41271 was published on 2021-11-15 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2.8.0:beta1:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2.8.0:beta2:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2.8.0:beta3:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2.8.0:beta4:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2.8.0:beta5:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2.8.0:beta6:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2.8.0:beta7:*:*:*:*:*:*

More vulnerabilities in Discourse

CVE-2021-41163 — Critical (CVSS 10.0): Discourse is an open source platform for community discussion. In affected versions maliciously crafted requests could…
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