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Fencer Intel
medium 5.2

CVE-2020-26231 json

Bypass of fix for CVE-2020-15247, Twig sandbox escape

published 5y ago modified last mo. also GHSA-r89v-cgv7-3jhx , EUVD-2020-1470

cvss
5.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits
0
none known

Summary

October is a free, open-source, self-hosted CMS platform based on the Laravel PHP Framework. A bypass of CVE-2020-15247 (fixed in 1.0.469 and 1.1.0) was discovered that has the same impact as CVE-2020-15247. An authenticated backend user with the cms.manage_pages, cms.manage_layouts, or cms.manage_partials permissions who would normally not be permitted to provide PHP code to be executed by the CMS due to cms.enableSafeMode being enabled is able to write specific Twig code to escape the Twig sandbox and execute arbitrary PHP. This is not a problem for anyone that trusts their users with those permissions to normally write & manage PHP within the CMS by not having cms.enableSafeMode enabled, but would be a problem for anyone relying on cms.enableSafeMode to ensure that users with those permissions in production do not have access to write & execute arbitrary PHP. Issue has been patched in Build 470 (v1.0.470) and v1.1.1.

Patch / fix

Is CVE-2020-26231 in your dependencies? 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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Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 5.2 CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L
NVD 3.1 6.7 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.4 AV:L/AC:M/Au:N/C:P/I:P/A:P
GitHub 3.1 5.2 CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L

Affected packages

ecosystem package affected fixed in
packagist october/cms
>=1.0.469, <1.0.470
1.0.470

Affected products

  • octobercms october

Classification

Weakness

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.