CVE-2025-6278: Upsonic server.py os.path.join path traversal

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-06-19 · updated 2026-06-17
Weakness: CWE-22

Description

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.

Affected products

Upsonic: through 0.55.6

References

https://github.com/Upsonic/Upsonic/issues/356
https://vuldb.com/?ctiid.313282
https://vuldb.com/?id.313282
https://vuldb.com/?submit.593096
https://github.com/Upsonic/Upsonic/issues/356

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