How severe is CVE-2021-35240?

CVE-2021-35240 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity low, and availability low.

Is CVE-2021-35240 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-35240?

CVE-2021-35240 affects Solarwinds Orion Platform. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-35240?

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

When was CVE-2021-35240 published?

CVE-2021-35240 was published on 2021-08-31 and last updated on 2026-06-17.

CVE-2021-35240

CVE-2021-35240 is a medium-severity vulnerability in Solarwinds Orion Platform 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)
CVSS v2: 3.5
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Solarwinds Orion Platform
Published: 2021-08-31
Last modified: 2026-06-17

Description

A security researcher stored XSS via a Help Server setting. This affects customers using Internet Explorer, because they do not support 'rel=noopener'.

Frequently asked questions

What is CVE-2021-35240?: A security researcher stored XSS via a Help Server setting. This affects customers using Internet Explorer, because they do not support 'rel=noopener'.
How severe is CVE-2021-35240?: CVE-2021-35240 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity low, and availability low.
Is CVE-2021-35240 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-35240?: CVE-2021-35240 affects Solarwinds Orion Platform. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-35240?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-35240 published?: CVE-2021-35240 was published on 2021-08-31 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:solarwinds:orion_platform:*:*:*:*:*:*:*:*

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