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Fencer Vulns
medium 6.5

CVE-2026-58403 json

Hugo symlink confinement bypass in os.ReadFile

published 2026-06-19 4 mo ago modified 2026-10-25 14 d ago also GHSA-c3wq-j5vh-68rc , GO-2026-5309 , EUVD-2026-41907

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

Hugo is a static site generator. From v0.123.0 through v0.163.0, Hugo's virtual filesystem is designed so that files under a mount cannot reach outside the mount tree, but a regression caused RootMappingFs.statRoot to call Stat, which follows symlinks, instead of Lstat, so a direct os.ReadFile "somefile" where somefile was a symlink pointing outside the mount would return the target's contents. This effectively let a symlink planted inside a theme or local mount read arbitrary files reachable to the user running hugo. This issue is fixed in v0.163.1.

Patch / fix

  • go github.com/gohugoio/hugo 0.163.1
  • gohugo hugo 0.163.1
  • hugo Debian 14 0.165.0-1

debian advisories DEBIAN-CVE-2026-58403

  • hugo hummingbird 1 0.163.3-0.1.hum1

red hat advisories RHSA-2026:36862

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-58403 updated cvss 6.5

github.com/gohugoio/hugo: Hugo: Information disclosure via symlink confinement bypass in virtual filesystem

  • Red Hat Hardened Images hugo 0.163.3-0.1.hum1
    fixed: vendor fix RHSA-2026:36862

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.9 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA 4.0 5.9 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/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
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
go github.com/gohugoio/hugo
>=0.123.0, <0.163.1
0.163.1

Affected products

  • gohugoio hugo

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.