What is GHSA-2mmf-4xwm-55rm?

SiYuan before v3.8.4 does not HTML-escape stored flashcard block content before interpolating it into the card-manager list markup. Block content returned by /api/riff/getRiffCards is inserted into a card item template in app/src/card/viewCards.ts and assigned to listElement.innerHTML, so content such as becomes an executable event-handler attribute. Because the SiYuan desktop (Electron) main window is created with nodeIntegration enabled and contextIsolation disabled, an administrator who opens the card manager on a workspace containing attacker-supplied flashcar

How severe is GHSA-2mmf-4xwm-55rm?

No CVSS score has been assigned to GHSA-2mmf-4xwm-55rm yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-2mmf-4xwm-55rm?

Affected package information for GHSA-2mmf-4xwm-55rm is not yet fully mapped. Check the official advisory links for details.

How do I fix GHSA-2mmf-4xwm-55rm?

Upgrade the affected component to the fixed release for GHSA-2mmf-4xwm-55rm, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.

How do I detect GHSA-2mmf-4xwm-55rm in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate GHSA-2mmf-4xwm-55rm if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is GHSA-2mmf-4xwm-55rm actively exploited in the wild?

No public exploit code has been indexed for GHSA-2mmf-4xwm-55rm yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-2mmf-4xwm-55rm?

GHSA-2mmf-4xwm-55rm has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 44th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-2mmf-4xwm-55rm?

GHSA-2mmf-4xwm-55rm is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-2mmf-4xwm-55rm published, and has it been updated?

GHSA-2mmf-4xwm-55rm was published on September 26, 2026 and was last updated on October 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

SiYuan before v3.8.4 Stored XSS via Unescaped…

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for GHSA-2mmf-4xwm-55rm.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs44th percentile — riskier than 44% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

SiYuan before v3.8.4 does not HTML-escape stored flashcard block content before interpolating it into the card-manager list markup. Block content returned by /api/riff/getRiffCards is inserted into a card item template in app/src/card/viewCards.ts and assigned to listElement.innerHTML, so content such as <img src=invalid onerror=...> becomes an executable event-handler attribute. Because the SiYuan desktop (Electron) main window is created with nodeIntegration enabled and contextIsolation disabled, an administrator who opens the card manager on a workspace containing attacker-supplied flashcard content (for example introduced through contribution or import) executes the attacker's script in a privileged renderer, which can lead to arbitrary code execution on the host. The affected endpoint remains behind authentication and administrator-role checks; this is an untrusted-content-to-privileged-renderer issue, not an authorization bypass.

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for GHSA-2mmf-4xwm-55rm, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

SiYuan before v3.8.4 does not HTML-escape stored flashcard block content before interpolating it into the card-manager list markup. Block content returned by /api/riff/getRiffCards is inserted into a card item template in app/src/card/viewCards.ts and assigned to listElement.innerHTML, so content such as <img src=invalid onerror=...> becomes an executable event-handler attribute. Because the SiYuan desktop (Electron) main window is created with nodeIntegration enabled and contextIsolation disabled, an administrator who opens the card manager on a workspace containing attacker-supplied flashcar

O3 Security · Impact-Aware SCA

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SiYuan before v3.8.4 Stored XSS via Unescaped Flashcard ContentGHSA-2mmf-4xwm-55rm