CVE-2026-106458
Backstage: Inconsistent repository filtering in Bitbucket Server catalog event updates
Backstage is an open framework for building developer portals. From 0.4.0 until 0.5.15, the @backstage/plugin-catalog-backend-module-bitbucket-server package is affected by inconsistent repository filtering in bitbucket server catalog event updates. Deployments using event-driven updates in the Bitbucket Server catalog provider may ingest catalog locations from repositories that are excluded by the provider's configured project, repository, or archived-repository filters. An authenticated Bitbucket Server user who can push to a filtered-out repository that remains readable by the configured Backstage integration can trigger a legitimate repository event. The affected event path may then add a Location for that repository even though scheduled discovery excludes it. This issue is fixed in version 0.5.15.
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
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.5
Backstage: Inconsistent repository filtering in Bitbucket Server catalog event updates
Backstage is an open framework for building developer portals. From 0.4.0 until 0.5.15, the @backstage/plugin-catalog-backend-module-bitbucket-server package is affected by inconsistent repository filtering in bitbucket server catalog event updates. Deployments using event-driven updates in the Bitbucket Server catalog provider may ingest catalog locations from repositories that are excluded by the provider's configured project, repository, or archived-repository filters. An authenticated Bitbucket Server user who can push to a filtered-out repository that remains readable by the configured Backstage integration can trigger a legitimate repository event. The affected event path may then add a Location for that repository even though scheduled discovery excludes it. This issue is fixed in version 0.5.15.
- Record
CVE-2026-106458- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
EUVDEUVD-2026-93992
6.5
Backstage is an open framework for building developer portals. From 0.4.0 until 0.5.15, the @backstage/plugin-catalog-backend-module-bitbucket-server package is affected by inconsistent repository filtering in bitbucket server catalog event updates. Deployments using event-driven updates in the Bitbucket Server catalog provider may ingest catalog locations from repositories that are excluded by the provider's configured project, repository, or archived-repository filters. An authenticated Bitbucket Server user who can push to a filtered-out repository that remains readable by the configured Backstage integration can trigger a legitimate repository event. The affected event path may then add a Location for that repository even though scheduled discovery excludes it. This issue is fixed in version 0.5.15.
- Record
EUVD-2026-93992- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-c36c-cf6r-ghgj
6.5
Backstage: Inconsistent repository filtering in Bitbucket Server catalog event updates
Impact
Deployments using event-driven updates in the Bitbucket Server catalog provider may ingest catalog locations from repositories that are excluded by the provider's configured project, repository, or archived-repository filters.
An authenticated Bitbucket Server user who can push to a filtered-out repository that remains readable by the configured Backstage integration can trigger a legitimate repository event. The affected event path may then add a Location for that repository even though scheduled discovery excludes it. This can cause catalog entities and metadata to be ingested from a repository that the operator did not intend to trust.
Deployments that do not enable event support for the Bitbucket Server catalog provider, do not configure repository filters, or whose integration credentials cannot read the filtered-out repositories are not affected.
Patches
Upgrade @backstage/plugin-catalog-backend-module-bitbucket-server to version 0.5.15 or later. The fixed package is available in Backstage v1.55.0.
Workarounds
- Disable event-driven updates for the Bitbucket Server catalog provider and rely on scheduled discovery until the patched package is deployed.
- Restrict the configured Bitbucket Server integration credentials so that they cannot read repositories that must remain outside the catalog trust boundary.
- Record
GHSA-c36c-cf6r-ghgj- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
NVD
6.5
Backstage is an open framework for building developer portals. From 0.4.0 until 0.5.15, the @backstage/plugin-catalog-backend-module-bitbucket-server package is affected by inconsistent repository filtering in bitbucket server catalog event updates. Deployments using event-driven updates in the Bitbucket Server catalog provider may ingest catalog locations from repositories that are excluded by the provider's configured project, repository, or archived-repository filters. An authenticated Bitbucket Server user who can push to a filtered-out repository that remains readable by the configured Backstage integration can trigger a legitimate repository event. The affected event path may then add a Location for that repository even though scheduled discovery excludes it. This issue is fixed in version 0.5.15.
- Record
CVE-2026-106458- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSV
6.5
Backstage: Inconsistent repository filtering in Bitbucket Server catalog event updates
Backstage is an open framework for building developer portals. From 0.4.0 until 0.5.15, the @backstage/plugin-catalog-backend-module-bitbucket-server package is affected by inconsistent repository filtering in bitbucket server catalog event updates. Deployments using event-driven updates in the Bitbucket Server catalog provider may ingest catalog locations from repositories that are excluded by the provider's configured project, repository, or archived-repository filters. An authenticated Bitbucket Server user who can push to a filtered-out repository that remains readable by the configured Backstage integration can trigger a legitimate repository event. The affected event path may then add a Location for that repository even though scheduled discovery excludes it. This issue is fixed in version 0.5.15.
- Record
CVE-2026-106458- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSVGHSA-c36c-cf6r-ghgj
6.5
Backstage: Inconsistent repository filtering in Bitbucket Server catalog event updates
Impact
Deployments using event-driven updates in the Bitbucket Server catalog provider may ingest catalog locations from repositories that are excluded by the provider's configured project, repository, or archived-repository filters.
An authenticated Bitbucket Server user who can push to a filtered-out repository that remains readable by the configured Backstage integration can trigger a legitimate repository event. The affected event path may then add a Location for that repository even though scheduled discovery excludes it. This can cause catalog entities and metadata to be ingested from a repository that the operator did not intend to trust.
Deployments that do not enable event support for the Bitbucket Server catalog provider, do not configure repository filters, or whose integration credentials cannot read the filtered-out repositories are not affected.
Patches
Upgrade @backstage/plugin-catalog-backend-module-bitbucket-server to version 0.5.15 or later. The fixed package is available in Backstage v1.55.0.
Workarounds
- Disable event-driven updates for the Bitbucket Server catalog provider and rely on scheduled discovery until the patched package is deployed.
- Restrict the configured Bitbucket Server integration credentials so that they cannot read repositories that must remain outside the catalog trust boundary.
- Record
GHSA-c36c-cf6r-ghgj- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@backstage/plugin-catalog-backend-module-bitbucket-servernpm |
0.4.0 up to 0.5.15 | 0.5.15 |
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-2026-106458 is a medium vulnerability (CVSS 6.5) in @backstage Plugin-catalog-backend-module-bitbucket-server, published October 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.27%, the 19th percentile. Fixed in @backstage/plugin-catalog-backend-module-bitbucket-server 0.5.15.
References
github.com/backstage/backstage/security/advisories/GHSA-c36c-cf6r-ghgj
github.com/backstage/backstage/commit/989db63b6f87c8fc04d440f296ad89e10c79b363
github.com/backstage/backstage/releases/tag/v1.55.0
nvd.nist.gov/vuln/detail/CVE-2026-106458
github.com/advisories/GHSA-c36c-cf6r-ghgj
github.com/CVEProject/cvelistV5/tree/main/cves/2026/106xxx/CVE-2026-106458.json
github.com/backstage/backstage