CVE-2026-24047
@backstage/cli-common has a possible `resolveSafeChildPath` Symlink Chain Bypass
Backstage is an open framework for building developer portals, and @backstage/cli-common provides config loading functionality used by the backend and command line interface of Backstage. Prior to version 0.1.17, the resolveSafeChildPath utility function in @backstage/backend-plugin-api, which is used to prevent path traversal attacks, failed to properly validate symlink chains and dangling symlinks. An attacker could bypass the path validation via symlink chains (creating link1 → link2 → /outside where intermediate symlinks eventually resolve outside the allowed directory) and dangling symlinks (creating symlinks pointing to non-existent paths outside the base directory, which would later be created during file operations). This function is used by Scaffolder actions and other backend components to ensure file operations stay within designated directories. This vulnerability is fixed in @backstage/backend-plugin-api version 0.1.17. Users should upgrade to this version or later. Some workarounds are available. Run Backstage in a containerized environment with limited filesystem access and/or restrict template creation to trusted users.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
@backstage/cli-common has a possible `resolveSafeChildPath` Symlink Chain Bypass
Backstage is an open framework for building developer portals, and @backstage/cli-common provides config loading functionality used by the backend and command line interface of Backstage. Prior to version 0.1.17, the resolveSafeChildPath utility function in @backstage/backend-plugin-api, which is used to prevent path traversal attacks, failed to properly validate symlink chains and dangling symlinks. An attacker could bypass the path validation via symlink chains (creating link1 → link2 → /outside where intermediate symlinks eventually resolve outside the allowed directory) and dangling symlinks (creating symlinks pointing to non-existent paths outside the base directory, which would later be created during file operations). This function is used by Scaffolder actions and other backend components to ensure file operations stay within designated directories. This vulnerability is fixed in @backstage/backend-plugin-api version 0.1.17. Users should upgrade to this version or later. Some workarounds are available. Run Backstage in a containerized environment with limited filesystem access and/or restrict template creation to trusted users.
- Record
CVE-2026-24047- CVSS 3.1
- 6.3 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-59, CWE-61
- Updated
- 2026-11-02
EUVDEUVD-2026-4138
Backstage is an open framework for building developer portals, and @backstage/cli-common provides config loading functionality used by the backend and command line interface of Backstage. Prior to version 0.1.17, the resolveSafeChildPath utility function in @backstage/backend-plugin-api, which is used to prevent path traversal attacks, failed to properly validate symlink chains and dangling symlinks. An attacker could bypass the path validation via symlink chains (creating link1 → link2 → /outside where intermediate symlinks eventually resolve outside the allowed directory) and dangling symlinks (creating symlinks pointing to non-existent paths outside the base directory, which would later be created during file operations). This function is used by Scaffolder actions and other backend components to ensure file operations stay within designated directories. This vulnerability is fixed in @backstage/backend-plugin-api version 0.1.17. Users should upgrade to this version or later. Some workarounds are available. Run Backstage in a containerized environment with limited filesystem access and/or restrict template creation to trusted users.
- Record
EUVD-2026-4138- CVSS 3.1
- 6.3 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-2p49-45hj-7mc9
@backstage/cli-common has a possible `resolveSafeChildPath` Symlink Chain Bypass
Impact
The resolveSafeChildPath utility function in @backstage/backend-plugin-api, which is used to prevent path traversal attacks, failed to properly validate symlink chains and dangling symlinks. An attacker could bypass the path validation by:
- Symlink chains: Creating
link1 → link2 → /outsidewhere intermediate symlinks eventually resolve outside the allowed directory - Dangling symlinks: Creating symlinks pointing to non-existent paths outside the base directory, which would later be created during file operations
This function is used by Scaffolder actions and other backend components to ensure file operations stay within designated directories.
Patches
This vulnerability is fixed in @backstage/backend-plugin-api version 0.1.17. Users should upgrade to this version or later.
Workarounds
- Run Backstage in a containerised environment with limited filesystem access
- Restrict template creation to trusted users
- Record
GHSA-2p49-45hj-7mc9- CVSS 3.1
- 6.3 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-59, CWE-61
- Updated
- 2026-11-02
NVD
Backstage is an open framework for building developer portals, and @backstage/cli-common provides config loading functionality used by the backend and command line interface of Backstage. Prior to version 0.1.17, the resolveSafeChildPath utility function in @backstage/backend-plugin-api, which is used to prevent path traversal attacks, failed to properly validate symlink chains and dangling symlinks. An attacker could bypass the path validation via symlink chains (creating link1 → link2 → /outside where intermediate symlinks eventually resolve outside the allowed directory) and dangling symlinks (creating symlinks pointing to non-existent paths outside the base directory, which would later be created during file operations). This function is used by Scaffolder actions and other backend components to ensure file operations stay within designated directories. This vulnerability is fixed in @backstage/backend-plugin-api version 0.1.17. Users should upgrade to this version or later. Some workarounds are available. Run Backstage in a containerized environment with limited filesystem access and/or restrict template creation to trusted users.
- Record
CVE-2026-24047- CVSS 3.1
- 6.3 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-59, CWE-61
- Updated
- 2026-11-02
OSV
@backstage/cli-common has a possible `resolveSafeChildPath` Symlink Chain Bypass
Backstage is an open framework for building developer portals, and @backstage/cli-common provides config loading functionality used by the backend and command line interface of Backstage. Prior to version 0.1.17, the resolveSafeChildPath utility function in @backstage/backend-plugin-api, which is used to prevent path traversal attacks, failed to properly validate symlink chains and dangling symlinks. An attacker could bypass the path validation via symlink chains (creating link1 → link2 → /outside where intermediate symlinks eventually resolve outside the allowed directory) and dangling symlinks (creating symlinks pointing to non-existent paths outside the base directory, which would later be created during file operations). This function is used by Scaffolder actions and other backend components to ensure file operations stay within designated directories. This vulnerability is fixed in @backstage/backend-plugin-api version 0.1.17. Users should upgrade to this version or later. Some workarounds are available. Run Backstage in a containerized environment with limited filesystem access and/or restrict template creation to trusted users.
- Record
CVE-2026-24047- CVSS 3.1
- 6.3 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-59, CWE-61
- Updated
- 2026-11-02
OSVGHSA-2p49-45hj-7mc9
@backstage/cli-common has a possible `resolveSafeChildPath` Symlink Chain Bypass
Impact
The resolveSafeChildPath utility function in @backstage/backend-plugin-api, which is used to prevent path traversal attacks, failed to properly validate symlink chains and dangling symlinks. An attacker could bypass the path validation by:
- Symlink chains: Creating
link1 → link2 → /outsidewhere intermediate symlinks eventually resolve outside the allowed directory - Dangling symlinks: Creating symlinks pointing to non-existent paths outside the base directory, which would later be created during file operations
This function is used by Scaffolder actions and other backend components to ensure file operations stay within designated directories.
Patches
This vulnerability is fixed in @backstage/backend-plugin-api version 0.1.17. Users should upgrade to this version or later.
Workarounds
- Run Backstage in a containerised environment with limited filesystem access
- Restrict template creation to trusted users
- Record
GHSA-2p49-45hj-7mc9- CVSS 3.1
- 6.3 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-59, CWE-61
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@backstage/cli-commonnpm |
through 0.1.16 | 0.1.17 |
@backstage/cli-commonnpm |
before 0.1.17 | 0.1.17 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-24047 is a medium vulnerability (CVSS 6.3) in Backstage, published January 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.53%, the 45th percentile. Fixed in @backstage/cli-common 0.1.17.
References
github.com/backstage/backstage/security/advisories/GHSA-2p49-45hj-7mc9
nvd.nist.gov/vuln/detail/CVE-2026-24047