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CVE-2014-3146· NVD / CVE Program· CNA redhat

Incomplete blacklist vulnerability in the lxml.html.clean module in lxml before 3.3.5 allows remote attackers to conduct cross-site scriptin

Incomplete blacklist vulnerability in the lxml.html.clean module in lxml before 3.3.5 allows remote attackers to conduct cross-site scripting (XSS) attacks via control characters in the link scheme to the clean_html function.

MediumCVSS 6.1 · v3.1—Proof of concept Fix available
Published
May 14, 2014
Updated
Jun 16, 2026
EPSS
6.3% · 93th percentile
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Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
24 / 40 · 6.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
2 / 30 · 6.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Affected systems

VendorProduct
lxmllxml

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • lxml lxmlup to 3.3.4 inclusive
  • lxml lxml0.5
  • lxml lxml0.5.1
  • lxml lxml0.6
  • lxml lxml0.7
  • lxml lxml0.8
  • lxml lxml0.9
  • lxml lxml0.9.1
  • lxml lxml0.9.2
  • lxml lxml1.0
  • lxml lxml1.0.1
  • lxml lxml1.0.2
  • lxml lxml1.0.3
  • lxml lxml1.0.4
  • lxml lxml1.1
  • lxml lxml1.1.1
  • lxml lxml1.1.2
  • lxml lxml1.2
  • lxml lxml1.2.1
  • lxml lxml1.3

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12lxmlbefore 3.3.5-13.3.5-1
Debian:6.0lxmlbefore 2.2.8-2+deb6u12.2.8-2+deb6u1
Debian:7lxmlbefore 2.3.2-1+deb7u12.3.2-1+deb7u1
PyPIlxmlbefore 3.3.53.3.5

Same product

lxml: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-49825lxml: javascript: URL bypass in Cleaner via xlink:href
    32Monitor
  • CVE-2022-2309NULL Pointer Dereference in lxml/lxml
    31Monitor
  • CVE-2026-41066lxml: Default configuration of iterparse() and ETCompatXMLParser() allows XXE to local files
    30Monitor
  • CVE-2021-43818HTML Cleaner allows crafted and SVG embedded scripts to pass through
    29Monitor
  • CVE-2021-28957An XSS vulnerability was discovered in python-lxml's clean module versions before 4.6.3.
    25Monitor
  • CVE-2020-27783A XSS vulnerability was discovered in python-lxml's clean module.
    25Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:lxml3.3.5-1 · Debian:12Package registry (OSV)
PyPI:lxml3.3.5Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Exploit-DB entry ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Exploit-DB entryremote2014-04-15

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-30 d
  2. Published
  3. TodaySep 30, 2026+4522 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

nvd-secondary

Root cause

User content is inserted into the page as HTML. The browser interprets the content as code rather than data.

The bug in code

The whole CWE-79 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
commentEl.innerHTML = comment.body;

Fixed

ts
commentEl.textContent = comment.body;

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records