Upsonic server.py os.path.join path traversal
Priority MEDIUM 56CWE-22Published · Updated
Key facts
- Attack vector
- Adjacent network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
A vulnerability classified as critical was found in Upsonic up to 0.55.6. This vulnerability affects the function os.path.join of the file markdown/server.py. The manipulation of the argument file.filename leads to path traversal. The exploit has been disclosed to the public and may be used.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00702 53rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA and NVD
Fix Fixed upsonic (PyPI): 0.56.0
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Upsonic | 0.55.0; 0.55.1; 0.55.2; 0.55.3; 0.55.4; 0.55.5; 0.55.6 | — | No fix listed | CNA |
| — | upsonic (PyPI) | before 0.56.0 | 0.56.0 | Patch available | GHSA-8jf4-fcjr-68c2 |
- Upsonic Vendor— Affected 0.55.0; 0.55.1; 0.55.2; 0.55.3; 0.55.4; 0.55.5; 0.55.6 Fixed in — No fix listed CNA
- upsonic (PyPI) Vendor— Affected before 0.56.0 Fixed in 0.56.0 Patch available GHSA-8jf4-fcjr-68c2
Remediation
- Fix · GHSA-8jf4-fcjr-68c2 upsonic (PyPI) Fixed in 0.56.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2025-6278
- 2026-10-03 Alias added: GHSA-8jf4-fcjr-68c2
References
Other 5
- https://github.com/Upsonic/Upsonic/pull/360
- https://github.com/Upsonic/Upsonic/commit/a54529acc6e4bfe28f4f5c80c058144348a306b7
- https://github.com/Upsonic/Upsonic
- https://github.com/Upsonic/Upsonic/blob/v0.55.6/src/upsonic/server/markdown/server/server.py#L39
- https://github.com/pypa/advisory-database/tree/main/vulns/upsonic/PYSEC-2025-67.yaml
More Upsonic vulnerabilities
- TI-2025-05681 Upsonic Pickle add_tool cloudpickle.loads deserialization CVSS 4.0MEDIUM 5.1
Sources
- CVE-2025-6278 · CVE Program
- CVE-2025-6278 · NVD
- FIRST EPSS
- GHSA-8jf4-fcjr-68c2 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences