CVE-2026-58403Network attack vector

Arbitrary file read via symlink-following regression

Published Jul 6, 2026 · Updated Jul 6, 2026

Improper link resolution in Hugo 0.123.0 through 0.163.0 allows remote attackers to read local files through a planted symlink. RootMappingFs.statRoot calls Stat instead of Lstat, so direct os.ReadFile lookups follow mount-tree symlinks and return target contents outside the mount. The attacker must place a symlink in a locally vendored theme or mount, or induce a site author to do so; GitHub-hosted module themes and directory walks are unaffected.

CVSS severity5.9
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper link resolution in Hugo 0.123.0 through 0.163.0 allows remote attackers to read local files through a planted symlink. RootMappingFs.statRoot calls Stat instead of Lstat, so direct os.ReadFile lookups follow mount-tree symlinks and return target contents outside the mount. The attacker must place a symlink in a locally vendored theme or mount, or induce a site author to do so; GitHub-hosted module themes and directory walks are unaffected.

The record

CVE
CVE-2026-58403
Published
Jul 6, 2026
Updated
Jul 6, 2026
Vendor
Hugo Authors
Product
Hugo
Classifications
CWE-59, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.123.0, < 0.163.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Hugo Authors · Hugoversion=>= 0.123.0, < 0.163.1

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
5.9GitHub, Inc.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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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