SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-54583

Malicious package index data could place an unsafe value in indexEntry->bundlefile, and the missing is_valid_bundle_filename() checks allowed downloaded package data to be written outside the intended cache location or to an unsafe destination name.

HIGH 8.3EPSS 0.54%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.54%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

mport is the MidnightBSD Package Manager. Prior to 2.7.8, libmport/fetch.c did not consistently reject empty, dot, dot-dot, or slash-containing bundle filenames before composing package download and write paths. Malicious package index data could place an unsafe value in indexEntry->bundlefile, and the missing is_valid_bundle_filename() checks allowed downloaded package data to be written outside the intended cache location or to an unsafe destination name. This issue is fixed in version 2.7.8.

CVSS 4.0
8.3 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/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/M
EPSS
0.54% probability · 45th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-22, CWE-73
Source
security-advisories@github.com
EPSS trend
0%3%5%26 October 2026: 0.54%26 October 202626 October 2026

EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.