# CVE-2026-126663: Contao 4.0.0 before 5.3.54, 5.4.0 before 5.7.17, and 6.0.0 before 6.0.6 Path Traversal via Image Insert Tag

Status: published. Published: 2026-11-11. Updated: 2026-11-11.

Contao 4.0.0 before 5.3.54, 5.4.0 before 5.7.17, and 6.0.0 before 6.0.6 contains a path traversal vulnerability that allows content editors to read image files anywhere on the filesystem via the {{image::}} insert tag. Attackers can embed percent-encoded sequences like ..%2f that pass Validator::isInsecurePath() before rawurldecode(), making the frontend resize and serve readable image files outside the files directory.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/contao/contao/commit/688c0f6213afbd000cd22ad0a44555eca80b40ab
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/contao/contao/commit/0f7989eb5b28d85dcd441ef22f80f8af4f56433e
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/contao/contao/commit/e820e3c9d79a5c07f274558513c8db08a79bf804

## Affected products and versions

- Contao / Contao (contao/core-bundle): ≥ 4.0.0; < 5.3.54 (affected, semver); ≥ 5.4.0-RC1; < 5.7.17 (affected, semver); ≥ 6.0.0-RC1; < 6.0.6 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 5.3 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 4.3 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-180

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/contao/contao/security/advisories/GHSA-r7cf-mfp4-r23h (CNA: VulnCheck; vendor-advisory)

- https://github.com/contao/contao/commit/688c0f6213afbd000cd22ad0a44555eca80b40ab (CNA: VulnCheck; patch)

- https://github.com/contao/contao/commit/0f7989eb5b28d85dcd441ef22f80f8af4f56433e (CNA: VulnCheck; patch)

- https://github.com/contao/contao/commit/e820e3c9d79a5c07f274558513c8db08a79bf804 (CNA: VulnCheck; patch)

- https://github.com/contao/contao/releases/tag/5.3.54 (CNA: VulnCheck; release-notes)

- https://github.com/contao/contao/releases/tag/5.7.17 (CNA: VulnCheck; release-notes)

- https://github.com/contao/contao/releases/tag/6.0.6 (CNA: VulnCheck; release-notes)

- https://github.com/contao/contao/blob/5.3.53/core-bundle/src/InsertTag/Resolver/LegacyInsertTag.php#L565-L582 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/contao-4.0.0-before-5.3.54-5.4.0-before-5.7.17-and-6.0.0-before-6.0.6-path-traversal-via-image-insert-tag (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-126663; retrieved 2026-11-11; source updated 2026-11-11

Revision: bb2d45a04a565bd77002e1525dc36e6c65f054c23bdedff7f1749f0767c8860b

Canonical: https://y2.dev/cve/CVE-2026-126663

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