How severe is CVE-2023-42458?

CVE-2023-42458 has a CVSS score of 3.7/10, rated LOW. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-42458?

CVE-2023-42458 affects the following packages: zope (PyPI), zope (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2023-42458?

Update zope to 4.8.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-42458 is resolved across your whole dependency graph.

How do I detect CVE-2023-42458 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zope, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-42458 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2023-42458 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2023-42458, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-42458?

CVE-2023-42458 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 54th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-42458?

CVE-2023-42458 is classified as Cross-site Scripting (XSS) (CWE-79), CWE-80 (CWE-80). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2023-42458 published, and has it been updated?

CVE-2023-42458 was published on September 21, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

LOW severity

CVE-2023-42458 — zope

LOWFix: zopefoundation/Zope@26a55db

CVE-2023-42458 is a low-severity (CVSS 3.7) Cross-site Scripting (XSS) vulnerability in zope. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for zope — see the affected versions and patch details below.

Zope vulnerable to Stored Cross Site Scripting with SVG images

Also known asGHSA-wm8q-9975-xh5vPYSEC-2026-2077

Published

Sep 21, 2023

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

1 known

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-42458.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

🐍zope🐍zope

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Impact

There is a stored cross site scripting vulnerability for SVG images.

Note that an image tag with an SVG image as source is never vulnerable, even when the SVG image contains malicious code. To exploit the vulnerability, an attacker would first need to upload an image, and then trick a user into following a specially crafted link.

All versions of Zope are impacted on sites that allow untrusted users to upload images.

Patches

Patches will be released in Zope 4.8.10 and 5.8.5.

Workarounds

Make sure the "Add Documents, Images, and Files" permission is only assigned to trusted roles. By default only the Manager has this permission.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`zope`	all versions	4.8.10`pip install --upgrade 'zope==4.8.10'`
🐍PyPI	`zope`	≥ 5.8.0&&< 5.8.5	5.8.5`pip install --upgrade 'zope==5.8.5'`

Affected Products

1 product · 2 configurations

Application

zopezope

≥ 5.0.0 && < 5.8.5

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Zope is an open-source web application server. Prior to versions 4.8.10 …

openwall.comNVDSep 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zope, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update zope to 4.8.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-42458 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Impact There is a stored cross site scripting vulnerability for SVG images. Note that an image tag with an SVG image as source is never vulnerable, even when the SVG image contains malicious code. To exploit the vulnerability, an attacker would first need to upload an image, and then trick a user into following a specially crafted link. All versions of Zope are impacted on sites that allow untrusted users to upload images. ### Patches Patches will be released in Zope 4.8.10 and 5.8.5. ### Workarounds Make sure the "Add Documents, Images, and Files" permission is only assigned to trust