GHSA-5rj5-gfmr-hrc3

Source

https://github.com/advisories/GHSA-5rj5-gfmr-hrc3

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-5rj5-gfmr-hrc3/GHSA-5rj5-gfmr-hrc3.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-5rj5-gfmr-hrc3

Aliases

CVE-2026-8426

Published

2026-05-21T21:30:38Z

Modified

2026-09-10T03:51:04Z

Severity

7.5 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator

Summary

Concrete CMS does not validate a CSRF token before processing requests to `/dashboard/extend/update/prepare_remote_upgrade/<remoteMPID>`

Details

Concrete CMS 9.5.0 and below does not validate a CSRF token before processing requests to /dashboard/extend/update/prepare_remote_upgrade/. An attacker who controls the remote package returned for a known marketplace item ID can overwrite the package PHP on disk and force its upgrade() method to execute in a single browser navigation. This results in remote code execution as the web server user. In order to be vulnerable, the victim must be passing canInstallPackages, victim site must be connected to the Concrete marketplace; and the attacker controls the package returned for a marketplace item ID already installed on the victim site. The Concrete CMS security team thanks @maru1009 for reporting this issue.

Database specific

{
    "cwe_ids":  [
        "CWE-352"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-06-24T18:19:48Z",
    "nvd_published_at":  "2026-05-21T21:16:34Z",
    "severity":  "HIGH"
}

References

Affected packages

Packagist / concrete5/concrete5

Package

Name: concrete5/concrete5
Purl: pkg:composer/concrete5/concrete5

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

9.5.1

Affected versions

8.*

8.0

8.0.1

8.0.2

8.0.3

8.1.0

8.2.0RC2

8.2.0

8.2.1

8.3.0

8.3.1

8.3.2

8.4.0RC3

8.4.0RC4

8.4.0

8.4.1

8.4.2

8.4.3

8.4.4

8.4.5

8.5.0RC1

8.5.0RC2

8.5.0

8.5.1

8.5.2

8.5.3

8.5.4

8.5.5

8.5.6RC1

8.5.6

8.5.7

8.5.8

8.5.9

8.5.10

8.5.11

8.5.12

8.5.13

8.5.14

8.5.15

8.5.16

8.5.17

8.5.18

8.5.19

8.5.20

8.5.21

9.*

9.0.0RC1

9.0.0RC3

9.0.0RC4

9.0.0

9.0.1

9.0.2

9.1.0

9.1.1

9.1.2

9.1.3

9.2.0RC2

9.2.0

9.2.1

9.2.2

9.2.3

9.2.4

9.2.5

9.2.6

9.2.7

9.2.8

9.2.9

9.3.0

9.3.1

9.3.2

9.3.3

9.3.4

9.3.5

9.3.6

9.3.7

9.3.8

9.3.9

9.4.0RC1

9.4.0RC2

9.4.0

9.4.1

9.4.2

9.4.3

9.4.4

9.4.5

9.4.6

9.4.7

9.4.8

9.5.0RC1

9.5.0RC2

9.5.0

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-5rj5-gfmr-hrc3/GHSA-5rj5-gfmr-hrc3.json"