CVE-2021-32660
TechDocs content sanitization bypass
Backstage is an open platform for building developer portals, and techdocs-common contains common functionalities for Backstage's TechDocs. In versions of @backstage/tehdocs-common prior to 0.6.4, a malicious internal actor is able to upload documentation content with malicious scripts. These scripts would normally be sanitized by the TechDocs frontend, but by tricking a user to visit the content via the TechDocs API, the content sanitazion will be bypassed. If the TechDocs API is hosted on the same origin as the Backstage app or other backend plugins, this may give access to sensitive data. The ability to upload malicious content may be limited by internal code review processes, unless the chosen TechDocs deployment method is to use an object store and the actor has access to upload files directly to that store. The vulnerability is patched in the 0.6.4 release of @backstage/techdocs-common.
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
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
TechDocs content sanitization bypass
Backstage is an open platform for building developer portals, and techdocs-common contains common functionalities for Backstage's TechDocs. In versions of @backstage/tehdocs-common prior to 0.6.4, a malicious internal actor is able to upload documentation content with malicious scripts. These scripts would normally be sanitized by the TechDocs frontend, but by tricking a user to visit the content via the TechDocs API, the content sanitazion will be bypassed. If the TechDocs API is hosted on the same origin as the Backstage app or other backend plugins, this may give access to sensitive data. The ability to upload malicious content may be limited by internal code review processes, unless the chosen TechDocs deployment method is to use an object store and the actor has access to upload files directly to that store. The vulnerability is patched in the 0.6.4 release of @backstage/techdocs-common.
- Record
CVE-2021-32660- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-77
- Updated
- 2026-11-02
EUVDEUVD-2021-1373
Backstage is an open platform for building developer portals, and techdocs-common contains common functionalities for Backstage's TechDocs. In versions of @backstage/tehdocs-common prior to 0.6.4, a malicious internal actor is able to upload documentation content with malicious scripts. These scripts would normally be sanitized by the TechDocs frontend, but by tricking a user to visit the content via the TechDocs API, the content sanitazion will be bypassed. If the TechDocs API is hosted on the same origin as the Backstage app or other backend plugins, this may give access to sensitive data. The ability to upload malicious content may be limited by internal code review processes, unless the chosen TechDocs deployment method is to use an object store and the actor has access to upload files directly to that store. The vulnerability is patched in the 0.6.4 release of @backstage/techdocs-common.
- Record
EUVD-2021-1373- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-pwhf-39xg-4rxw
Script injection
Impact
A malicious internal actor is able to upload documentation content with malicious scripts. These scripts would normally be sanitized by the TechDocs frontend, but by tricking a user to visit the content via the TechDocs API, the content sanitazion will be bypassed. If the TechDocs API is hosted on the same origin as the Backstage app or other backend plugins, this may give access to sensitive data.
The ability to upload malicious content may be limited by internal code review processes, unless the chosen TechDocs deployment method is to use an object store and the actor has access to upload files directly to that store.
Patches
The vulnerability is patched in the 0.6.4 release of @backstage/techdocs-common.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the Backstage repository
- Visit our chat, linked to in Backstage README
- Record
GHSA-pwhf-39xg-4rxw- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-77, CWE-434
- Updated
- 2026-11-02
NVD
Backstage is an open platform for building developer portals, and techdocs-common contains common functionalities for Backstage's TechDocs. In versions of @backstage/tehdocs-common prior to 0.6.4, a malicious internal actor is able to upload documentation content with malicious scripts. These scripts would normally be sanitized by the TechDocs frontend, but by tricking a user to visit the content via the TechDocs API, the content sanitazion will be bypassed. If the TechDocs API is hosted on the same origin as the Backstage app or other backend plugins, this may give access to sensitive data. The ability to upload malicious content may be limited by internal code review processes, unless the chosen TechDocs deployment method is to use an object store and the actor has access to upload files directly to that store. The vulnerability is patched in the 0.6.4 release of @backstage/techdocs-common.
- Record
CVE-2021-32660- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - CVSS 2.0
- 5.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:N - Weakness
- CWE-77, CWE-434
- Updated
- 2026-11-02
OSV
Backstage is an open platform for building developer portals, and techdocs-common contains common functionalities for Backstage's TechDocs. In versions of @backstage/tehdocs-common prior to 0.6.4, a malicious internal actor is able to upload documentation content with malicious scripts. These scripts would normally be sanitized by the TechDocs frontend, but by tricking a user to visit the content via the TechDocs API, the content sanitazion will be bypassed. If the TechDocs API is hosted on the same origin as the Backstage app or other backend plugins, this may give access to sensitive data. The ability to upload malicious content may be limited by internal code review processes, unless the chosen TechDocs deployment method is to use an object store and the actor has access to upload files directly to that store. The vulnerability is patched in the 0.6.4 release of @backstage/techdocs-common.
- Record
CVE-2021-32660- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
OSVGHSA-pwhf-39xg-4rxw
Script injection
Impact
A malicious internal actor is able to upload documentation content with malicious scripts. These scripts would normally be sanitized by the TechDocs frontend, but by tricking a user to visit the content via the TechDocs API, the content sanitazion will be bypassed. If the TechDocs API is hosted on the same origin as the Backstage app or other backend plugins, this may give access to sensitive data.
The ability to upload malicious content may be limited by internal code review processes, unless the chosen TechDocs deployment method is to use an object store and the actor has access to upload files directly to that store.
Patches
The vulnerability is patched in the 0.6.4 release of @backstage/techdocs-common.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the Backstage repository
- Visit our chat, linked to in Backstage README
- Record
GHSA-pwhf-39xg-4rxw- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-434, CWE-77
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@backstage/techdocs-commonnpm |
before 0.6.4 | 0.6.4 |
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-2021-32660 is a medium vulnerability (CVSS 6.8) in Backstage, published June 3, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.27%, the 69th percentile. Fixed in @backstage/techdocs-common 0.6.4.