CVE-2023-40587Network attack vector

Adjacent-file disclosure via NUL-truncated static path

Published Aug 25, 2023 · Updated Feb 13, 2025

Path traversal in Pylons Project Pyramid 2.0.0 through 2.0.1 allows remote attackers to read an adjacent index.html via a crafted URL. Pyramid static-view validation accepts a NUL-bearing segment that Python 3.11 os.path.normpath truncates, resolving the request one directory above the configured root. Exposure requires Python 3.11.0 through 3.11.4, a full-filesystem static-view path, and an index.html directly above it; no other file is disclosed.

CVSS severity5.3
Medium
EPSS probability0.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in Pylons Project Pyramid 2.0.0 through 2.0.1 allows remote attackers to read an adjacent index.html via a crafted URL. Pyramid static-view validation accepts a NUL-bearing segment that Python 3.11 os.path.normpath truncates, resolving the request one directory above the configured root. Exposure requires Python 3.11.0 through 3.11.4, a full-filesystem static-view path, and an index.html directly above it; no other file is disclosed.

The record

CVE
CVE-2023-40587
Published
Aug 25, 2023
Updated
Feb 13, 2025
Vendor
Pylons Project
Product
Pyramid
Classifications
CWE-22, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record 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=>= 2.0.0, < 2.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Pylons Project · Pyramidversion=>= 2.0.0, < 2.0.2

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A: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-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
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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