CVE-2026-117538

REDAXO before 5.21.0 Reflected XSS via Packages API function Parameter

publishedCWE-79

REDAXO before 5.21.0 contains a reflected cross-site scripting vulnerability in the backend packages API, where the function parameter is concatenated into an error message rendered without HTML escaping. Attackers can lure an authenticated backend user to a crafted link containing a valid CSRF token, executing JavaScript that performs same-origin actions or reads DOM data.

Technical severity2.1 lowCVSS 4.0 · CNA: VulnCheck

Published2026-10-27Source updated 2026-11-04

Collected2026-11-044 attributed sources

Fixes and workarounds

Fix

redaxo/source (Packagist): OSV reports a fixed version 5.21.0. Check the advisory for supported release branches.

Source: OSV GHSA-xq4j-g85q-wf97

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
core redaxo	≥ 0; < 5.21.0 (affected, semver) 5.21.0 (unaffected, semver) Other versions: unaffected	CNA: VulnCheck
redaxo/source `redaxo/source` Packagist	5.10.0 (affected, Packagist) 5.10.0-beta1 (affected, Packagist) 5.10.0-beta2 (affected, Packagist) 5.10.1 (affected, Packagist) 5.11.0 (affected, Packagist) 5.11.0-beta1 (affected, Packagist) 5.11.1 (affected, Packagist) 5.11.2 (affected, Packagist) 5.12.0 (affected, Packagist) 5.12.0-beta1 (affected, Packagist) 5.12.0-beta2 (affected, Packagist) 5.12.0-beta3 (affected, Packagist) 5.12.1 (affected, Packagist) 5.13.0 (affected, Packagist) 5.13.0-beta1 (affected, Packagist) 5.13.0-beta2 (affected, Packagist) 5.13.1 (affected, Packagist) 5.13.2 (affected, Packagist) 5.13.3 (affected, Packagist) 5.14.0 (affected, Packagist) 5.14.0-beta1 (affected, Packagist) 5.14.0-beta2 (affected, Packagist) 5.14.1 (affected, Packagist) 5.14.2 (affected, Packagist) 5.14.3 (affected, Packagist) 5.15.0 (affected, Packagist) 5.15.0-beta1 (affected, Packagist) 5.15.1 (affected, Packagist) 5.16.0 (affected, Packagist) 5.16.0-beta1 (affected, Packagist) 5.16.1 (affected, Packagist) 5.17.0 (affected, Packagist) 5.17.1 (affected, Packagist) 5.18.0 (affected, Packagist) 5.18.1 (affected, Packagist) 5.18.2 (affected, Packagist) 5.18.3 (affected, Packagist) 5.19.0 (affected, Packagist) 5.20.0 (affected, Packagist) 5.20.1 (affected, Packagist) 5.20.2 (affected, Packagist) 5.21.0-beta1 (affected, Packagist) Ecosystem version events: introduced 0; fixed 5.21.0 Source events (ECOSYSTEM) `[ { "introduced": "0" }, { "fixed": "5.21.0" } ]` Other versions: unaffected	OSV GHSA-xq4j-g85q-wf97

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
4.0 / 2.1 low	`CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N`	CNA: VulnCheck
3.1 / 4.1 medium	`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L`	CNA: VulnCheck
4.0 / 2.1 low	`CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X`	NVD: [email protected]
3.1 / 4.1 medium	`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L`	NVD: [email protected]

Exploit evidence

https://github.com/redaxo/core/security/advisories/GHSA-xq4j-g85q-wf97
exploit · ADP: CISA-ADP

References

https://github.com/redaxo/core/security/advisories/GHSA-xq4j-g85q-wf97CNA: VulnCheck · vendor-advisory
https://www.vulncheck.com/advisories/redaxo-before-5.21.0-reflected-xss-via-packages-api-function-parameterCNA: VulnCheck · third-party-advisory
https://github.com/redaxo/core/security/advisories/GHSA-xq4j-g85q-wf97ADP: CISA-ADP · exploit
https://github.com/redaxo/core/security/advisories/GHSA-xq4j-g85q-wf97[email protected]
https://www.vulncheck.com/advisories/redaxo-before-5.21.0-reflected-xss-via-packages-api-function-parameter[email protected]
https://github.com/redaxo/core/security/advisories/GHSA-xq4j-g85q-wf97134c704f-9b21-4f2e-91b3-4a467353bcc0
https://github.com/advisories/GHSA-xq4j-g85q-wf97OSV / GitHub Security Advisories · advisory
https://osv.dev/vulnerability/GHSA-xq4j-g85q-wf97OSV / GitHub Security Advisories · osv

Prioritization

CISA known exploited vulnerabilities

No KEV listing in collected sources. This does not establish that exploitation is absent.

EPSS

0.18% estimated probability of exploitation in the next 30 days; percentile 7.51.
Assessed 2026-11-04 by FIRST.

SSVC

Exploitation: poc
Automatable: no
Technical impact: partial

ADP: CISA-ADP · 2026-11-04

Provenance

CNA: VulnCheck
Source updated 2026-11-04
Retrieved 2026-11-04

NVD
Source updated 2026-11-04
Retrieved 2026-11-04

OSV / GitHub Security Advisories
Source updated 2026-10-28
Retrieved 2026-11-04

FIRST EPSS
Source updated Not reported
Retrieved 2026-11-04

Disclosure revision
68d4510aafba14f69f9f29eabaccfc078e1258cbc81920bd21d2a0c57a84de1f

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