CVE-2021-36849Network attack vector

Stored script execution in another user's browser

Published Jul 20, 2022 · Updated Apr 28, 2026

Stored XSS in MashShare 3.8.1 and earlier allows remote authenticated users with administrator access to inject script via unspecified input. Public records do not disclose the affected setting, input field, code locus, or the operation that permits persistent script content. Exploitation requires administrator-level privileges and another user to view the stored content; the script then runs in that user's browser.

CVSS severity3.4
Low
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in MashShare 3.8.1 and earlier allows remote authenticated users with administrator access to inject script via unspecified input. Public records do not disclose the affected setting, input field, code locus, or the operation that permits persistent script content. Exploitation requires administrator-level privileges and another user to view the stored content; the script then runs in that user's browser.

The record

CVE
CVE-2021-36849
Published
Jul 20, 2022
Updated
Apr 28, 2026
Vendor
René Hermenau
Product
MashShare
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 20, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 3.8.1 <=3.8.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

René Hermenau · MashShareversion=<= 3.8.1 <=3.8.1

Published CVSS scores

4.8NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
3.4PatchstackCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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