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NVD / CVE Program· CNA GitHub_M

CVE-2024-28234: Contao has insufficient BBCode sanitizer

MediumCVSS 4.7 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 18/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.57% (FIRST EPSS).
  • 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.
  • Fixed version: contao/comments-bundle (Packagist) 4.13.40, 5.3.4.

Low priority for now. Upgrade to contao/comments-bundle (Packagist) 4.13.40, 5.3.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Contao is an open source content management system. Starting in version 2.0.0 and prior to versions 4.13.40 and 5.3.4, it is possible to inject CSS styles via BBCode in comments. Installations are only affected if BBCode is enabled. Contao versions 4.13.40 and 5.3.4 have a patch for this issue. As a workaround, disable BBCode for comments.

Published
Apr 9, 2024
Updated
Jun 17, 2026
EPSS
0.5% · 47th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
4.7
CNA · GitHub_M
4.3
0.4 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2024-28234

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
contaocontao

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • contao contao

    • >= 2.0.0, < 4.13.40, >= 5.0.0, < 5.3.4affected

Affected versions

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

  • contao contao2.0 and later · before 4.13.40
  • contao contao5.0.0 and later · before 5.3.4

Package-level exposure

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

EcosystemPackageAffected rangeFix
Packagistcontao/comments-bundlefrom 2.0.0 · before 4.13.404.13.40
Packagistcontao/comments-bundlefrom 5.0.0-RC1 · before 5.3.45.3.4

Same product

contao: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-26265Contao Managed Edition v1.5.0 was discovered to contain a remote command execution (RCE) vulnerability via the component php_cli parameter.
    48Plan
  • CVE-2019-11512Contao 4.x allows SQL Injection.
    39Monitor
  • CVE-2026-107845Contao: Cross-site scripting in the comments bundle
    37Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2024-28190Apr 9, 2024 · Contao core bundle vulnerable to cross site scripting in the file manager
    21Monitor
  • ← EarlierCVE-2024-28191Apr 9, 2024 · Contao may have unencoded insert tags in the frontend
    21Monitor
  • Later →CVE-2024-28235Apr 9, 2024 · Contao possible cookie sharing with external domains while checking protected pages for broken links
    26Monitor

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
Packagist:contao/comments-bundle4.13.40Package registry (OSV)
Packagist:contao/comments-bundle5.3.4Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

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.

No dated events beyond publication.

Patch and commit links

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

Variant candidates

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

  • CVE-2024-281910 days apartContao may have unencoded insert tags in the frontend
    21Monitor

Not on record for this CVE: EPSS history · researcher credit · public bounty program.

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
none
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
None
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CVSS vector

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

nvd-primary

Attack context

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

References

Show all references (3 more)

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

All records