VulnerabilityPublished 6 Oct 2026

CVE-2026-106458: backstage · Incorrect Authorization

Affects backstageSource GCVE Database

Not known to be exploited · CVSS 6.5 Medium : upgrade to 0.5.15 when convenient.

Data as of 27 Oct 2026, 21:15 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 0.5.15

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade @backstage/plugin-catalog-backend-module-bitbucket-server to 0.5.15.

Affected software

Product	Affected	Fixed in
npm@backstage/plugin-catalog-backend-module-bitbucket-server`pkg:npm/@backstage/plugin-catalog-backend-module-bitbucket-server`Other threats	Affected >=0.4.0 <0.5.15	Fixed in 0.5.15

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade the @backstage/plugin-catalog-backend-module-bitbucket-server package to version 0.5.15 or later, where the issue is fixed. No other mitigation is indicated by the vendor advisory.

Description

CVE-2026-106458 is an authorization vulnerability in the Backstage open framework affecting the @backstage/plugin-catalog-backend-module-bitbucket-server package versions from 0.4.0 up to 0.5.15. The issue involves inconsistent filtering of Bitbucket Server repositories during event-driven catalog updates, allowing an authenticated user with push access to a filtered-out repository to cause the system to ingest catalog locations from that repository despite it being excluded by configured filters. This could lead to unauthorized inclusion of repository data in the catalog. The vulnerability is fixed in version 0.5.15.

Impact

An authenticated Bitbucket Server user with push access to a repository excluded by Backstage's configured filters can cause the system to ingest and add that repository's location to the catalog. This leads to unauthorized inclusion of repository data, impacting the integrity of the catalog. The vulnerability does not affect confidentiality or availability but has a medium severity impact on integrity.

Summary

Backstage versions from 0.4.0 until 0.5.15 of the @backstage/plugin-catalog-backend-module-bitbucket-server package suffer from an incorrect authorization flaw (CWE-863) due to inconsistent repository filtering during Bitbucket Server catalog event updates. Specifically, when using event-driven updates, repositories that should be excluded based on project, repository, or archived-repository filters may still be ingested if an authenticated Bitbucket Server user with push permissions triggers a repository event. This bypasses the intended filtering logic, potentially adding unauthorized repository locations to the catalog. The issue is resolved in Backstage version 0.5.15.

CWE-863Incorrect Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #17OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Oct 2026, 21:15 UTC

WeaknessesCWE-863

Technical details

References

Community reviews

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