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Fencer Intel
medium 4.3

CVE-2026-126663 json

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

published yesterday modified 21h ago also EUVD-2026-123405 , GHSA-r7cf-mfp4-r23h

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository contao/contao. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
—
no EPSS score yet
public exploits
0
none known

Summary

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.

Patch / fix

  • Contao Contao 5.3.54, 5.7.17, 6.0.6

Is CVE-2026-126663 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CVSS scores

assigned by version score vector
CNA 4.0 5.3 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
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CNA 4.0 5.3 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/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 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected products

  • Contao Contao

Classification

Weakness
  • CWE-180 Incorrect Behavior Order: Validate Before Canonicalize

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of contao/contao published their own advisory on GitHub. Reviewed sources take precedence over it.