How severe is CVE-2021-22886?

CVE-2021-22886 has a CVSS 3.x base score of 6.1, 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-2021-22886 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22886?

CVE-2021-22886 primarily affects Rocket.chat. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-22886?

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

When was CVE-2021-22886 published?

CVE-2021-22886 was published on 2021-03-26 and last updated on 2026-06-17.

CVE-2021-22886

CVE-2021-22886 is a medium-severity vulnerability in Rocket.chat with a CVSS 3.x base score of 6.1. 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: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Rocket.chat
Published: 2021-03-26
Last modified: 2026-06-17

Description

Rocket.Chat before 3.11, 3.10.5, 3.9.7, 3.8.8 is vulnerable to persistent cross-site scripting (XSS) using nested markdown tags allowing a remote attacker to inject arbitrary JavaScript in a message. This flaw leads to arbitrary file read and RCE on Rocket.Chat desktop app.

Frequently asked questions

What is CVE-2021-22886?: Rocket.Chat before 3.11, 3.10.5, 3.9.7, 3.8.8 is vulnerable to persistent cross-site scripting (XSS) using nested markdown tags allowing a remote attacker to inject arbitrary JavaScript in a message. This flaw leads to arbitrary file read and RCE on Rocket.Chat desktop app.
How severe is CVE-2021-22886?: CVE-2021-22886 has a CVSS 3.x base score of 6.1, 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-2021-22886 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22886?: CVE-2021-22886 primarily affects Rocket.chat. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-22886?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-22886 published?: CVE-2021-22886 was published on 2021-03-26 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:a:rocket.chat:rocket.chat:*:*:*:*:*:*:*:*
cpe:2.3:a:rocket.chat:rocket.chat:3.11.0:rc0:*:*:*:*:*:*
cpe:2.3:a:rocket.chat:rocket.chat:3.11.0:rc1:*:*:*:*:*:*
cpe:2.3:a:rocket.chat:rocket.chat:3.11.0:rc2:*:*:*:*:*:*
cpe:2.3:a:rocket.chat:rocket.chat:3.11.0:rc3:*:*:*:*:*:*
cpe:2.3:a:rocket.chat:rocket.chat:3.11.0:rc4:*:*:*:*:*:*
cpe:2.3:a:rocket.chat:rocket.chat:3.11.0:rc5:*:*:*:*:*:*
cpe:2.3:a:rocket.chat:rocket.chat:3.11.0:rc6:*:*:*:*:*:*
cpe:2.3:a:rocket.chat:rocket.chat:3.11.0:rc7:*:*:*:*:*:*

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