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NVD / CVE Program· CNA GitHub_M

CVE-2023-38490: Kirby XML External Entity (XXE) vulnerability in the XML data handler

Noroxi assessment

Priority: Plan (action score 41/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1.7% (FIRST EPSS); higher than 77.1% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: getkirby/cms (Packagist) 3.6.6.3, 3.7.5.2, 3.8.4.1.
  • Severity is disputed: the assigning authority (CNA) scores it 6.8, NVD 10.0.

Add it to your regular patch cycle. Upgrade to getkirby/cms (Packagist) 3.6.6.3, 3.7.5.2, 3.8.4.1 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

Kirby is a content management system. A vulnerability in versions prior to 3.5.8.3, 3.6.6.3, 3.7.5.2, 3.8.4.1, and 3.9.6 only affects Kirby sites that use the `Xml` data handler (e.g. `Data::decode($string, 'xml')`) or the `Xml::parse()` method in site or plugin code. The Kirby core does not use any of the affected methods. XML External Entities (XXE) is a little used feature in the XML markup language that allows to include data from external files in an XML structure. If the name of the external file can be controlled by an attacker, this becomes a vulnerability that can be abused for various system impacts like the disclosure of internal or confidential data that is stored on the server (arbitrary file disclosure) or to perform network requests on behalf of the server (server-side request forgery, SSRF). Kirby's `Xml::parse()` method used PHP's `LIBXML_NOENT` constant, which enabled the processing of XML external entities during the parsing operation. The `Xml::parse()` method is used in the `Xml` data handler (e.g. `Data::decode($string, 'xml')`). Both the vulnerable method and the data handler are not used in the Kirby core. However they may be used in site or plugin code, e.g. to parse RSS feeds or other XML files. If those files are of an external origin (e.g. uploaded by a user or retrieved from an external URL), attackers may be able to include an external entity in the XML file that will then be processed in the parsing process. Kirby sites that don't use XML parsing in site or plugin code are *not* affected. The problem has been patched in Kirby 3.5.8.3, 3.6.6.3, 3.7.5.2, 3.8.4.1, and 3.9.6. In all of the mentioned releases, the maintainers have removed the `LIBXML_NOENT` constant as processing of external entities is out of scope of the parsing logic. This protects all uses of the method against the described vulnerability.

CriticalCVSS 10.0 · v3.1—Proof of concept Fix available
Published
Jul 27, 2023
Updated
Jun 17, 2026
EPSS
1.7% · 77th percentile

Report tools

JSON

Action score

41

Plan

Add it to your regular patch cycle.

CVSS
40 / 40 · 10.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 1.7%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
10.0
CNA · GitHub_M
6.8
3.2 point gap

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/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
  • Proof of concept exists, no weaponized module
  • A fix has been released

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

Follow CVE-2023-38490

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
getkirbykirby

Affected versions

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

  • getkirby kirby3.5.0 and later · before 3.5.8.3
  • getkirby kirby3.6.0 and later · before 3.6.6.3
  • getkirby kirby3.7.0 and later · before 3.7.5.2
  • getkirby kirby3.8.0 and later · before 3.8.4.1
  • getkirby kirby3.9.0 and later · before 3.9.6

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.

  • getkirby kirby

    • < 3.5.8.3, >= 3.6.0, < 3.6.6.3, >= 3.7.0, < 3.7.5.2, >= 3.8.0, < 3.8.41, >= 3.9.0, < 3.9.6affected

Package-level exposure

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

EcosystemPackageAffected rangeFix
Packagistgetkirby/cmsfrom 3.6.0 · before 3.6.6.33.6.6.3
Packagistgetkirby/cmsfrom 3.7.0 · before 3.7.5.23.7.5.2
Packagistgetkirby/cmsfrom 3.8.0 · before 3.8.4.13.8.4.1
Packagistgetkirby/cmsfrom 3.9.0 · before 3.9.63.9.6
Packagistgetkirby/cmsbefore 3.5.8.33.5.8.3

Same product

getkirby: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-44177Kirby: Pre-authentication path traversal and PHP file inclusion during user lookup
    36Monitor
  • CVE-2026-54003Kirby: External Initialization of the Panel on reverse proxy setups with the `Forwarded` header
    36Monitor
  • CVE-2020-26255PHP Phar archives could be uploaded and executed in Kirby
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2023-38488Jul 27, 2023 · Kirby vulnerable to field injection in the KirbyData text storage handler
    35Monitor
  • ← EarlierCVE-2023-38489Jul 27, 2023 · Kirby vulnerable to Insufficient Session Expiration after a password change
    29Monitor
  • Later →CVE-2023-38491Jul 27, 2023 · Kirby vulnerable to Cross-site scripting (XSS) from MIME type auto-detection of uploaded files
    21Monitor

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:getkirby/cms3.5.8.3Package registry (OSV)
Packagist:getkirby/cms3.6.6.3Package registry (OSV)
Packagist:getkirby/cms3.7.5.2Package registry (OSV)
Packagist:getkirby/cms3.8.4.1Package registry (OSV)
Packagist:getkirby/cms3.9.6Package 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

  • Proof-of-concept repository on GitHub ×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
Proof-of-concept repository on GitHubstars:12023-07-28

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. Published
  2. First PoC+1 d
  3. TodayOct 31, 2026+1192 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

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

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.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · 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
None
Scope
Changed
Confidentiality impact
High
Integrity impact
High
Availability impact
None

Weakness class (CWE)

CWE-611 · Improper Restriction of XML External Entity Reference

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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References

Show all references (6 more)

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

All records