CVE-2026-27156 json
NiceGUI has XSS via Code Injection
published 8mo ago modified 3mo ago also EUVD-2026-8544 , GHSA-78qv-3mpx-9cqq , PYSEC-2026-2232
- cvss
- 6.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 9%
- public exploits
- 0
- none known
Summary
NiceGUI is a Python-based UI framework. Prior to version 3.8.0, several NiceGUI APIs that execute methods on client-side elements (`Element.run_method()`, `AgGrid.run_grid_method()`, `EChart.run_chart_method()`, and others) use an `eval()` fallback in the JavaScript-side `runMethod()` function. When user-controlled input is passed as the method name, an attacker can inject arbitrary JavaScript that executes in the victim's browser. Additionally, `Element.run_method()` and `Element.get_computed_prop()` used string interpolation instead of `json.dumps()` for the method/property name, allowing quote injection to break out of the intended string context. Version 3.8.0 contains a fix.
Patch / fix
Is CVE-2026-27156 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 8mo ago
Exploit prediction
0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| GitHub | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| OSV | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | nicegui | <3.8.0 |
3.8.0 |
Affected products
- zauberzeug nicegui
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/zauberzeug/nicegui/commit/1861f59cc374ca0dc9d970b157ef3774720f8dbf
web, patch
-
github.com
/zauberzeug/nicegui/security/advisories/GHSA-78qv-3mpx-9cqq
web, mitigation, vendor-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-27156
advisory
-
github.com
/zauberzeug/nicegui
package
Sources
- CVE List CVE-2026-27156
- GitHub Advisory GHSA-78qv-3mpx-9cqq
- NVD CVE-2026-27156
- OSV PYSEC-2026-2232
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.