How severe is CVE-2021-21087?

CVE-2021-21087 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-21087 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 37% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21087?

CVE-2021-21087 primarily affects Adobe Coldfusion. In total, 29 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-21087?

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

When was CVE-2021-21087 published?

CVE-2021-21087 was published on 2021-04-15 and last updated on 2026-06-17.

CVE-2021-21087

CVE-2021-21087 is a medium-severity vulnerability in Adobe Coldfusion with a CVSS 3.x base score of 5.4. Its EPSS exploit-prediction score of 37% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 37% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Adobe Coldfusion
Published: 2021-04-15
Last modified: 2026-06-17

Description

Adobe Coldfusion versions 2016 (update 16 and earlier), 2018 (update 10 and earlier) and 2021.0.0.323925 are affected by an Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability. An attacker could abuse this vulnerability to execute arbitrary JavaScript code in context of the current user. Exploitation of this issue requires user interaction.

Frequently asked questions

What is CVE-2021-21087?: Adobe Coldfusion versions 2016 (update 16 and earlier), 2018 (update 10 and earlier) and 2021.0.0.323925 are affected by an Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability. An attacker could abuse this vulnerability to execute arbitrary JavaScript code in context of the current user. Exploitation of this issue requires user interaction.
How severe is CVE-2021-21087?: CVE-2021-21087 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-21087 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 37% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21087?: CVE-2021-21087 primarily affects Adobe Coldfusion. In total, 29 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-21087?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-21087 published?: CVE-2021-21087 was published on 2021-04-15 and last updated on 2026-06-17.

References

https://helpx.adobe.com/security/products/coldfusion/apsb21-16.html

Affected products (29)

cpe:2.3:a:adobe:coldfusion:2016:-:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update1:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update10:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update11:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update12:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update13:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update14:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update15:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update16:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update2:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update3:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update4:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update5:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update6:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update7:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update8:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2016:update9:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:-:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update1:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update10:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update2:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update3:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update4:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update5:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update6:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update7:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update8:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2018:update9:*:*:*:*:*:*
cpe:2.3:a:adobe:coldfusion:2021.0.0.323925:*:*:*:*:*:*:*

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