Every CVE Search/ Get API key

CVE-2026-56384

Craft CMS - Missing Authorization in assets/preview-thumb Endpoint

5.3 MediumFix available

Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
Low
User interaction
None

What an attacker can affect

Confidentiality
Low
Integrity
None
Availability
None

Exploit likelihood

0.33%Up 0.1 points since Jun 23, 2026
90%50%10%1%

What each source reports

CVE List Score used 5.3

Craft CMS - Missing Authorization in assets/preview-thumb Endpoint

Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.

Record
CVE-2026-56384
CVSS 4.0
5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness
CWE-862
Updated
2026-11-02
EUVDEUVD-2026-38178 5.3

Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.

Record
EUVD-2026-38178
CVSS 4.0
5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Updated
2026-11-02
GitHub AdvisoriesGHSA-x76w-8c62-48mg 5.3

Craft CMS: Authenticated "assets/preview-thumb" discloses signed fallback transform preview link to CP users without asset-view permission

Summary

A user with Control Panel access but without permission to view a target private asset can call assets/preview-thumb and receive preview HTML that contains a signed fallback transform link for that private asset.

Details

Root-cause analysis:

  1. The endpoint accepts an attacker-controlled assetId.
  2. Asset is resolved, and thumbnail HTML is returned.
  3. No explicit asset-view permission check is performed before preview generation.

Impact

Type:

  1. Missing authorization
  2. Unauthorized preview-link disclosure

Affected deployments:

  1. Craft sites with control panel users who have partial permissions and private assets.

Security consequence:

  1. A control panel user without asset-view permission can still obtain signed preview transform link data for private assets.
  2. This may increase private asset exposure risk depending on deployment and endpoint chaining.

Resources

https://github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27

Record
GHSA-x76w-8c62-48mg
CVSS 4.0
5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness
CWE-200, CWE-862
Updated
2026-11-02
GitHub AdvisoriesGHSA-xj2c-g5xp-4p47 5.3

Duplicate Advisory: Craft CMS: Authenticated "assets/preview-thumb" discloses signed fallback transform preview link to CP users without asset-view permission

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-x76w-8c62-48mg. This link is maintained to preserve external references.

Original Description

Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.

Record
GHSA-xj2c-g5xp-4p47
CVSS 4.0
5.3 MediumCVSS: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
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness
CWE-862
Updated
2026-11-02
NVD 5.3

Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.

Record
CVE-2026-56384
CVSS 4.0
5.3 MediumCVSS: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
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness
CWE-862
Updated
2026-11-02
OSV 5.3

Craft CMS - Missing Authorization in assets/preview-thumb Endpoint

Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.

Record
CVE-2026-56384
CVSS 4.0
5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness
CWE-862
Updated
2026-11-02
OSVGHSA-x76w-8c62-48mg 5.3

Craft CMS: Authenticated "assets/preview-thumb" discloses signed fallback transform preview link to CP users without asset-view permission

Summary

A user with Control Panel access but without permission to view a target private asset can call assets/preview-thumb and receive preview HTML that contains a signed fallback transform link for that private asset.

Details

Root-cause analysis:

  1. The endpoint accepts an attacker-controlled assetId.
  2. Asset is resolved, and thumbnail HTML is returned.
  3. No explicit asset-view permission check is performed before preview generation.

Impact

Type:

  1. Missing authorization
  2. Unauthorized preview-link disclosure

Affected deployments:

  1. Craft sites with control panel users who have partial permissions and private assets.

Security consequence:

  1. A control panel user without asset-view permission can still obtain signed preview transform link data for private assets.
  2. This may increase private asset exposure risk depending on deployment and endpoint chaining.

Resources

https://github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27

Record
GHSA-x76w-8c62-48mg
CVSS 4.0
5.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness
CWE-200, CWE-862
Updated
2026-11-02
OSVGHSA-xj2c-g5xp-4p47 5.3

Duplicate Advisory: Craft CMS: Authenticated "assets/preview-thumb" discloses signed fallback transform preview link to CP users without asset-view permission

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-x76w-8c62-48mg. This link is maintained to preserve external references.

Original Description

Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.

Record
GHSA-xj2c-g5xp-4p47
CVSS 4.0
5.3 MediumCVSS: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
CVSS 3.1
4.3 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness
CWE-862
Updated
2026-11-02
OSVCLSA-2026-1784077481 No score

TuxCare security update for craftcms/cms (3 CVEs)

TuxCare rebuilt craftcms/cms to address 3 CVEs. Fixed in 3.9.15-p6+tuxcare.

Record
CLSA-2026-1784077481
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
craftcms/cms
Packagist
 4.0.0-RC1 to 4.17.7
4.17.8
craftcms/cms
Packagist
 5.0.0-RC1 to 5.9.13
5.9.14
craftcms/cms
TuxCare:Packagist
From an advisory covering 2 CVEs
 3.9.15 up to 3.9.15-p6+tuxcare, plus listed versions
3.9.15-p1+tuxcare3.9.15-p2+tuxcare3.9.15-p3+tuxcare3.9.15-p4+tuxcare3.9.15-p5+tuxcare
3.9.15-p6+tuxcare
craftcms/cms
Packagist
 4.0.0-RC1 up to 4.17.8, plus listed versions
4.0.04.0.0-RC24.0.0-RC34.0.0.14.0.1
Show 45 moreShow less
4.0.24.0.34.0.44.0.54.0.5.14.0.5.24.0.64.1.04.1.0.14.1.0.24.1.14.1.24.1.34.1.44.1.4.14.10.04.10.0-beta.14.10.0-beta.24.10.14.10.24.10.34.10.44.10.54.10.64.10.74.10.84.11.04.11.0.14.11.0.24.11.14.11.24.11.34.11.44.11.54.12.04.12.14.12.24.12.34.12.44.12.4.14.12.54.12.64.12.6.14.12.74.12.8
4.17.8
craftcms/cms
Packagist
 5.0.0-RC1 up to 5.9.14, plus listed versions
5.0.05.0.15.0.25.0.35.0.4
Show 45 moreShow less
5.0.55.0.65.1.05.1.15.1.105.1.25.1.35.1.45.1.55.1.65.1.75.1.85.1.95.2.05.2.0-beta.15.2.0-beta.25.2.0-beta.35.2.0-beta.45.2.0-beta.55.2.0-beta.65.2.15.2.105.2.25.2.35.2.45.2.4.15.2.55.2.65.2.75.2.85.2.95.3.05.3.0-beta.15.3.0-beta.25.3.0.15.3.0.25.3.0.35.3.15.3.25.3.35.3.45.3.55.3.65.4.05.4.0.1
5.9.14

History

History
RecordedChangedSources
affected, facts
affected
affected, aliases, products, published, referencesEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-56384 is a medium vulnerability (CVSS 5.3) in Craftcms Cms, published June 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.33%, the 26th percentile. Fixed in craftcms/cms 4.17.8.

References

This page doesn't list everything

Left out here: 298 versions. The JSON record has them.

Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open