vulnerability / NVI-00008187 / Revision 5
Kirby: Self cross-site scripting (self-XSS) in the writer field
GitHub lists this reviewed advisory for getkirby/cms, getkirby/cms. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.4 HIGH (4.0)
security-advisories@github.com severity; no combined Null risk score.
0.432%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.37669. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
getkirby/cms
source listed<= 4.9.3
### TL;DR This vulnerability affects Kirby sites that use the writer field in any blueprint. It was possible to include a scripting link as the target of a link (or email link). This link target would then be clickable by the user who entered it. A successful attack commonly requires knowledge of the content structure by the attacker as well as social engineering of a user with access to the Panel. The attack *cannot* be automated. In Kirby's default configuration, the vulnerability is limited to self-XSS and *cannot* directly affect other users or visitors of the site. Panel plugins that are directly using the `` component may also be affected by stored XSS if they don't sanitize the resulting HTML before saving it to the content. **This vulnerability is of high severity for affected sites.** ---- ### Introduction Cross-site scripting (XSS) is a type of vulnerability that allows attackers to execute any kind of JavaScript code inside the Panel session of the same or other users. In the Panel, a harmful script can, for example, trigger requests to Kirby's API with the permissions of the victim. *Self* cross-site scripting (self-XSS) typically involves a user inad
getkirby/cms
source listed>= 5.0.0-alpha.1, <= 5.4.3
### TL;DR This vulnerability affects Kirby sites that use the writer field in any blueprint. It was possible to include a scripting link as the target of a link (or email link). This link target would then be clickable by the user who entered it. A successful attack commonly requires knowledge of the content structure by the attacker as well as social engineering of a user with access to the Panel. The attack *cannot* be automated. In Kirby's default configuration, the vulnerability is limited to self-XSS and *cannot* directly affect other users or visitors of the site. Panel plugins that are directly using the `` component may also be affected by stored XSS if they don't sanitize the resulting HTML before saving it to the content. **This vulnerability is of high severity for affected sites.** ---- ### Introduction Cross-site scripting (XSS) is a type of vulnerability that allows attackers to execute any kind of JavaScript code inside the Panel session of the same or other users. In the Panel, a harmful script can, for example, trigger requests to Kirby's API with the permissions of the victim. *Self* cross-site scripting (self-XSS) typically involves a user inad
getkirby/cms
source listedECOSYSTEM: introduced 0; fixed 4.9.4
### TL;DR This vulnerability affects Kirby sites that use the writer field in any blueprint. It was possible to include a scripting link as the target of a link (or email link). This link target would then be clickable by the user who entered it. A successful attack commonly requires knowledge of the content structure by the attacker as well as social engineering of a user with access to the Panel. The attack *cannot* be automated. In Kirby's default configuration, the vulnerability is limited to self-XSS and *cannot* directly affect other users or visitors of the site. Panel plugins that are directly using the `` component may also be affected by stored XSS if they don't sanitize the resulting HTML before saving it to the content. **This vulnerability is of high severity for affected sites.** ---- ### Introduction Cross-site scripting (XSS) is a type of vulnerability that allows attackers to execute any kind of JavaScript code inside the Panel session of the same or other users. In the Panel, a harmful script can, for example, trigger requests to Kirby's API with the permissions of the victim. *Self* cross-site scripting (self-XSS) typically involves a user inad
getkirby/cms
source listedECOSYSTEM: introduced 5.0.0-alpha.1; fixed 5.4.4
### TL;DR This vulnerability affects Kirby sites that use the writer field in any blueprint. It was possible to include a scripting link as the target of a link (or email link). This link target would then be clickable by the user who entered it. A successful attack commonly requires knowledge of the content structure by the attacker as well as social engineering of a user with access to the Panel. The attack *cannot* be automated. In Kirby's default configuration, the vulnerability is limited to self-XSS and *cannot* directly affect other users or visitors of the site. Panel plugins that are directly using the `` component may also be affected by stored XSS if they don't sanitize the resulting HTML before saving it to the content. **This vulnerability is of high severity for affected sites.** ---- ### Introduction Cross-site scripting (XSS) is a type of vulnerability that allows attackers to execute any kind of JavaScript code inside the Panel session of the same or other users. In the Panel, a harmful script can, for example, trigger requests to Kirby's API with the permissions of the victim. *Self* cross-site scripting (self-XSS) typically involves a user inad
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
- vendor patch
The original advisory lists fixed boundaries 4.9.4 for getkirby/cms. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 5.4.4 for getkirby/cms. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-rhj6-r49h-5932 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- GHSA-rhj6-r49h-5932 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-49276 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
- CVE-2026-49276 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 5 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 3 ·
Source facts changed; compare the preserved prior revision.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.