NiceGUI's unvalidated chunk size parameter in media routes can cause memory exhaustion
Published Mar 24, 2026
6.9
MEDIUMCVSS 4.0
EPSS 0.69%
Description
NiceGUI is a Python-based UI framework. Prior to version 3.9.0, NiceGUI's app.add_media_file() and app.add_media_files() media routes accept a user-controlled query parameter that influences how files are read during streaming. The parameter is passed to the range-response implementation without validation, allowing an attacker to bypass chunked streaming and force the server to load entire files into memory at once. With large media files and concurrent requests, this can lead to excessive memory consumption, degraded performance, or denial of service. This issue has been patched in version 3.9.0.
Affected products
-
- Version < 3.9.0StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Zauberzeug | Nicegui | n/a |
|
- < 3.9.0
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
1 other source (NVD) ▾
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
1 other source (GHSA) ▾
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Mar 25, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Mar–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.69% (0.00692) | 51.11th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.60% (0.00599) | 43.80th | v5 (v2026.06.15) |
| Mar 25, 2026 | 0.03% (0.00025) | 6.89th | v4 (v2025.03.14) |
References (5)
- https://github.com/advisories/GHSA-w5g8-5849-vj76 Advisory
- https://github.com/zauberzeug/nicegui/commit/9026962b8c4f3f225c98b2fbc35aa6b60cb3495b x_refsource_MISCPatch
- https://github.com/zauberzeug/nicegui/releases/tag/v3.9.0 x_refsource_MISCProductRelease Notes
- https://github.com/zauberzeug/nicegui/security/advisories/GHSA-w5g8-5849-vj76 x_refsource_CONFIRMMitigationVendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-33332
| Link | Providers | Tags |
|---|---|---|
| https://github.com/advisories/GHSA-w5g8-5849-vj76 | Advisory | |
| https://github.com/zauberzeug/nicegui/commit/9026962b8c4f3f225c98b2fbc35aa6b60cb3495b | x_refsource_MISCPatch | |
| https://github.com/zauberzeug/nicegui/releases/tag/v3.9.0 | x_refsource_MISCProductRelease Notes | |
| https://github.com/zauberzeug/nicegui/security/advisories/GHSA-w5g8-5849-vj76 | x_refsource_CONFIRMMitigationVendor Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2026-33332 |
Change history (0)
No recorded changes yet.