Is CVE-2026-48777 in the CISA KEV catalog?

No. CVE-2026-48777 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-48777?

CVE-2026-48777 has a CVSS v4 base score of 9.3 (CRITICAL).

What is the EPSS score for CVE-2026-48777?

CVE-2026-48777 has an EPSS score of 0.45% (36th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-48777

CRITICAL

9.3

CVSS v4

NVD

Description

FileBrowser Quantum is a free, self-hosted, web-based file manager. Versions prior to 1.3.2-stable, 1.4.0-beta and 1.4.1-beta are vulnerable to Path Traversal through the publicPatchHandler in backend/http/public.go which joins user-controlled fromPath and toPath body fields with the trusted d.share.Path BEFORE the downstream sanitizer runs. Because filepath.Join collapses .. segments during the join, the sanitizer in resourcePatchHandler never sees the traversal and the move/copy/rename operates on a path outside the shared directory. The same root-cause pattern was patched for the bulk DELETE endpoint as CVE-2026-44542 (GHSA-fwj3-42wh-8673), but the PATCH handler with the identical pattern was not updated. A public share link with AllowModify=true is sufficient to exploit this. Anyone holding such a link can move, copy, or rename arbitrary files within the share owner's source root. This issue has been fixed in versions 1.3.3-stable and 1.4.2-beta.

CWE-22Path Traversal

CVSS v4 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

Impact

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/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

Exploit Intelligence

0.45%probability of exploitation in 30 days

36thpercentile

Low risk: more likely to be exploited than 36% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-17.