How severe is CVE-2016-4855?

CVE-2016-4855 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2016-4855?

CVE-2016-4855 affects the following packages: adodb/adodb-php (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2016-4855?

Update adodb/adodb-php to 5.20.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-4855 is resolved across your whole dependency graph.

How do I detect CVE-2016-4855 in my Packagist dependencies?

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

How do I mitigate CVE-2016-4855 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-2016-4855 actively exploited in the wild?

No public exploit code has been indexed for CVE-2016-4855 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2016-4855?

CVE-2016-4855 has an EPSS (Exploit Prediction Scoring System) score of 1.9%, placing it in the 80th 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-2016-4855?

CVE-2016-4855 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type 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-2016-4855 published, and has it been updated?

CVE-2016-4855 was published on May 12, 2017 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

MEDIUM severity

CVE-2016-4855 — adodb-php

MEDIUMFix: ADOdb/ADOdb@ecb93d8

CVE-2016-4855 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in adodb/adodb-php. A fix is available for adodb/adodb-php — see the affected versions and patch details below.

ADOdb Cross-site scripting vulnerability in old test script

Also known asGHSA-hhfw-xxhm-pf32

Published

May 12, 2017

Updated

Oct 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 30, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs80th percentile — riskier than 80% 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

1 pkg affected

🐘adodb/adodb-php

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

Description

Cross-site scripting vulnerability in ADOdb versions prior to 5.20.6 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`adodb/adodb-php`	all versions	5.20.6`composer require adodb/adodb-php:^5.20.6`

Affected Products

1 product · 1 configurations

Application

adodbadodb_project

≤ 5.20.5

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for adodb/adodb-php, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update adodb/adodb-php to 5.20.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-4855 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.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

UbuntuMEDIUM

USN-6825-1Ubuntu

Frequently Asked Questions

Cross-site scripting vulnerability in ADOdb versions prior to 5.20.6 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

O3 Security · Impact-Aware SCA

Is CVE-2016-4855 in your dependencies?

Find it across Packagist, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CWE Classification

CWE-79Cross-site Scripting (XSS)

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

ADOdb

4.7/10

Code-Review1/10

Maintained6/10

Branch-ProtectionN/A

Assessed Oct 26, 2026

Timeline

Disclosed

May 12, 2017

Last updated

Oct 20, 2026

Identifiers

CVE-2016-4855

GHSA-hhfw-xxhm-pf32

References

Advisoryjvn.jp · index Advisorysecurityfocus.com Advisorygithub.com Advisorysecurity.gentoo.org · 201701 59 Advisorynvd.nist.gov · CVE 2016 4855 Webgithub.com · ecb93d8c1fd3bbde62aca9c3a13c32f077da2da8 Webgithub.com · CVE 2016 4855.yaml Packagegithub.com · ADOdb

Related vulnerabilities

Also affects adodb/adodb-php

This CVE is medium severity; 5 of 5 other CVEs affecting adodb/adodb-php are rated as high or higher (top: critical).

CVE-2025-54119CVE-2025-46337GHSA-h63c-xvpf-264jCVE-2016-7405CVE-2021-3850

Same weakness: CWE-79

This CVE is medium severity; 3 of 3 other CVEs with CWE-79 are rated as high or higher (top: critical).

CVE-2026-113787CVE-2026-44267CVE-2026-96632Browse all CWE-79

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 20, 2026