Bugsink: Issue event views can show an event from another project if its UUID is known

Description

Description

Bugsink issue event pages accept a direct event identifier from the URL and, in affected versions, look up that event without also requiring it to belong to the issue in the URL.

This is a project-boundary authorization issue: a logged-in user with access to one project can view another project’s event data through an issue they are allowed to access. However, the issue is mitigated by two factors. First, the attacker needs to already know a valid target event UUID; there is no event enumeration path here, and guessing UUIDs is not practical. Second, Bugsink is commonly self-hosted within a single trust domain, and Hosted Bugsink gives each tenant a separate Bugsink instance, so cross-project access does not normally imply cross-tenant access.

The affected views include the stacktrace, details, and breadcrumbs pages for an issue event.

This has been fixed by requiring direct event lookups to match both the authorized issue and the project.

Impact

Low-severity cross-project event data exposure, requiring authentication and prior knowledge of a valid event UUID.

Basic information

Type
reviewed
Severity
low
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-06-05 21:43:23 UTC
Updated
2026-06-05 21:43:26 UTC
GitHub reviewed
2026-06-05 21:43:23 UTC
NVD published
2026-05-26

EPSS Score

Score Percentile
0.03% 8.52%

CVSS Scores

Base score Version Severity Vector
3.1 3.1
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

CWEs

CWE id Name
CWE-639 Authorization Bypass Through User-Controlled Key

Credits

  • nuiifornet (reporter)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
pip bugsink < 2.2.0 2.2.0

References

cvelogic Threat Intelligence