How severe is CVE-2023-28357?

CVE-2023-28357 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2023-28357 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-28357?

CVE-2023-28357 affects Rocket.chat. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-28357?

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

When was CVE-2023-28357 published?

CVE-2023-28357 was published on 2023-05-11 and last updated on 2026-06-17.

CVE-2023-28357

CVE-2023-28357 is a medium-severity vulnerability in Rocket.chat with a CVSS 3.x base score of 4.3. 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 4.3)
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Rocket.chat
Published: 2023-05-11
Last modified: 2026-06-17

Description

A vulnerability has been identified in Rocket.Chat, where the ACL checks in the Slash Command /mute occur after checking whether a user is a member of a given channel, leaking private channel members to unauthorized users. This allows authenticated users to enumerate whether a username is a member of a channel that they do not have access to.

Frequently asked questions

What is CVE-2023-28357?: A vulnerability has been identified in Rocket.Chat, where the ACL checks in the Slash Command /mute occur after checking whether a user is a member of a given channel, leaking private channel members to unauthorized users. This allows authenticated users to enumerate whether a username is a member of a channel that they do not have access to.
How severe is CVE-2023-28357?: CVE-2023-28357 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2023-28357 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-28357?: CVE-2023-28357 affects Rocket.chat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-28357?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-28357 published?: CVE-2023-28357 was published on 2023-05-11 and last updated on 2026-06-17.

References

https://hackerone.com/reports/1445810

Affected products (1)

cpe:2.3:a:rocket.chat:rocket.chat:*:*:*:*:*:*:*:*

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