CVE-2020-11083
Stored XSS in October
In October from version 1.0.319 and before version 1.0.466, a user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. This has been fixed in 1.0.466. For users of the RainLab.Blog plugin, this has also been fixed in 1.4.1.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Stored XSS in October
In October from version 1.0.319 and before version 1.0.466, a user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. This has been fixed in 1.0.466. For users of the RainLab.Blog plugin, this has also been fixed in 1.4.1.
- Record
CVE-2020-11083- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2020-0645
In October from version 1.0.319 and before version 1.0.466, a user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. This has been fixed in 1.0.466. For users of the RainLab.Blog plugin, this has also been fixed in 1.4.1.
- Record
EUVD-2020-0645- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-w4pj-7p68-3vgv
Stored XSS in October
Impact
A user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field.
Patches
Issue has been patched in Build 466 (v1.0.466) & RainLab.Blog v1.4.1 by restricting the ability to store JS in markdown to only users that have been explicitly granted the backend.allow_unsafe_markdown permission.
Workarounds
Apply https://github.com/octobercms/october/commit/9ecfb4867baae14a0d3f99f5b5c1e8a979ae8746 & https://github.com/rainlab/blog-plugin/commit/6ae19a6e16ef3ba730692bc899851342c858bb94 to your installation manually if unable to upgrade to Build 466 or v1.4.1 of RainLab.Blog (if using that plugin).
References
Reported by Sivanesh Ashok
For more information
If you have any questions or comments about this advisory:
- Email us at [email protected]
Threat assessment:
<img width="1100" alt="Screen Shot 2020-03-31 at 2 01 52 PM" src="https://user-images.githubusercontent.com/7253840/78070158-8f7ef580-7358-11ea-950c-226533f6a0a3.png">
- Record
GHSA-w4pj-7p68-3vgv- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
In October from version 1.0.319 and before version 1.0.466, a user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. This has been fixed in 1.0.466. For users of the RainLab.Blog plugin, this has also been fixed in 1.4.1.
- Record
CVE-2020-11083- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N - CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
In October from version 1.0.319 and before version 1.0.466, a user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. This has been fixed in 1.0.466. For users of the RainLab.Blog plugin, this has also been fixed in 1.4.1.
- Record
CVE-2020-11083- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-w4pj-7p68-3vgv
Stored XSS in October
Impact
A user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field.
Patches
Issue has been patched in Build 466 (v1.0.466) & RainLab.Blog v1.4.1 by restricting the ability to store JS in markdown to only users that have been explicitly granted the backend.allow_unsafe_markdown permission.
Workarounds
Apply https://github.com/octobercms/october/commit/9ecfb4867baae14a0d3f99f5b5c1e8a979ae8746 & https://github.com/rainlab/blog-plugin/commit/6ae19a6e16ef3ba730692bc899851342c858bb94 to your installation manually if unable to upgrade to Build 466 or v1.4.1 of RainLab.Blog (if using that plugin).
References
Reported by Sivanesh Ashok
For more information
If you have any questions or comments about this advisory:
- Email us at [email protected]
Threat assessment:
<img width="1100" alt="Screen Shot 2020-03-31 at 2 01 52 PM" src="https://user-images.githubusercontent.com/7253840/78070158-8f7ef580-7358-11ea-950c-226533f6a0a3.png">
- Record
GHSA-w4pj-7p68-3vgv- CVSS 3.1
- 3.5 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
october/backendPackagist |
1.0.319 up to 1.0.466 | 1.0.466 |
october/backendPackagist |
1.0.319 up to 1.0.466, plus listed versions v1.0.319v1.0.320v1.0.321v1.0.322v1.0.323 Show 45 moreShow lessv1.0.324v1.0.325v1.0.326v1.0.327v1.0.328v1.0.329v1.0.330v1.0.331v1.0.332v1.0.333v1.0.334v1.0.335v1.0.336v1.0.337v1.0.338v1.0.339v1.0.340v1.0.341v1.0.342v1.0.343v1.0.344v1.0.345v1.0.346v1.0.347v1.0.348v1.0.349v1.0.350v1.0.351v1.0.352v1.0.353v1.0.354v1.0.355v1.0.356v1.0.357v1.0.358v1.0.359v1.0.360v1.0.361v1.0.362v1.0.363v1.0.364v1.0.365v1.0.366v1.0.367v1.0.368 |
1.0.466 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-11083 is a low vulnerability (CVSS 3.5) in October Cms October, published July 14, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.15%, the 67th percentile. Fixed in october/backend 1.0.466.
References
github.com/octobercms/october/security/advisories/GHSA-w4pj-7p68-3vgv
packetstormsecurity.com/files/158730/October-CMS-Build-465-XSS-File-Read-File-Deletion-CSV-Injection.html
seclists.org/fulldisclosure/2020/Aug/2
nvd.nist.gov/vuln/detail/CVE-2020-11083
Left out here: 97 versions. The JSON record has them.