How severe is CVE-2021-39175?

CVE-2021-39175 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-39175 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39175?

CVE-2021-39175 affects Hedgedoc. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-39175?

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

When was CVE-2021-39175 published?

CVE-2021-39175 was published on 2021-08-30 and last updated on 2026-06-17.

CVE-2021-39175

CVE-2021-39175 is a high-severity vulnerability in Hedgedoc with a CVSS 3.x base score of 8.1. 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: High (CVSS 3.x base score 8.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Hedgedoc
Published: 2021-08-30
Last modified: 2026-06-17

Description

HedgeDoc is a platform to write and share markdown. In versions prior to 1.9.0, an unauthenticated attacker can inject arbitrary JavaScript into the speaker-notes of the slide-mode feature by embedding an iframe hosting the malicious code into the slides or by embedding the HedgeDoc instance into another page. The problem is patched in version 1.9.0. There are no known workarounds aside from upgrading.

Frequently asked questions

What is CVE-2021-39175?: HedgeDoc is a platform to write and share markdown. In versions prior to 1.9.0, an unauthenticated attacker can inject arbitrary JavaScript into the speaker-notes of the slide-mode feature by embedding an iframe hosting the malicious code into the slides or by embedding the HedgeDoc instance into another page. The problem is patched in version 1.9.0. There are no known workarounds aside from upgrading.
How severe is CVE-2021-39175?: CVE-2021-39175 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-39175 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39175?: CVE-2021-39175 affects Hedgedoc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-39175?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-39175 published?: CVE-2021-39175 was published on 2021-08-30 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:hedgedoc:hedgedoc:*:*:*:*:*:*:*:*

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