SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-52781

An attacker injects data-controller="poll-for-changes" into a work package description, causing Stimulus.js to mount a controller that fetches an attacker-uploaded attachment and passes it to renderStreamMessage().

MEDIUM 6.4EPSS 0.25%

Does this matter?

Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.

Description

OpenProject is open-source, web-based project management software. Prior to 17.3.3 and 17.4.1, the HTML sanitizer grants <macro> elements unrestricted data-* attributes via :data wildcard. An attacker injects data-controller="poll-for-changes" into a work package description, causing Stimulus.js to mount a controller that fetches an attacker-uploaded attachment and passes it to renderStreamMessage(). This executes arbitrary Turbo Stream actions — including redirect_to — in every victim's authenticated browser session, redirecting them to an attacker-controlled server. This vulnerability is fixed in 17.3.3 and 17.4.1.

CVSS 3.1
6.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
EPSS
0.25% probability · 16th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-79
Source
security-advisories@github.com
EPSS trend
0%3%5%27 October 2026: 0.25%27 October 202627 October 2026

EPSS 0.3% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.