CVE-2026-1854Network attack vector

Stored XSS via unescaped flag shortcode attributes

Published Mar 21, 2026 · Updated Mar 21, 2026

Stored XSS in the flag shortcode in nosoycesaros Post Flagger 1.1 and earlier allows remote authenticated users to inject scripts. The flag shortcode handler accepts user-supplied attributes without sufficient sanitization and emits them into page output without the escaping needed for their HTML context. Contributor-level access is required to store a crafted shortcode, and the injected script executes when a user visits the affected page.

CVSS severity6.4
Medium
EPSS probability0.24%
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 the flag shortcode in nosoycesaros Post Flagger 1.1 and earlier allows remote authenticated users to inject scripts. The flag shortcode handler accepts user-supplied attributes without sufficient sanitization and emits them into page output without the escaping needed for their HTML context. Contributor-level access is required to store a crafted shortcode, and the injected script executes when a user visits the affected page.

The record

CVE
CVE-2026-1854
Published
Mar 21, 2026
Updated
Mar 21, 2026
Vendor
nosoycesaros
Product
Post Flagger
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 21, 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=* <=1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

nosoycesaros · Post Flaggerversion=* <=1.1

Published CVSS scores

6.4WordfenceCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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