Bugsink: DOS using large numbers of event tags
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.
Summary
Bugsink is a self-hosted error tracking tool. Prior to version 2.2.2, Bugsink stores every set of custom tags supplied with an incoming event, allowing a caller with a valid project DSN to submit an unusually large tag set and force excessive tag-row writes. Because Bugsink uses a single-writer database architecture, the expensive write transaction delays digestion of other events and causes a temporary ingestion denial of service. Version 2.2.2 applies the configurable MAX_EVENT_TAGS limit before storage. The impact is limited to availability for an instance accepting the event and does not expose stored data, modify existing events, or allow code execution. This issue is fixed in version 2.2.2.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| bugsink | bugsink | before 2.2.2 | 2.2.2 | Patch available | CNA |
| — | bugsink (PyPI) | before 2.2.2 | 2.2.2 | Patch available | GHSA-5x67-j5xg-c5gj |
- bugsink Vendorbugsink Affected before 2.2.2 Fixed in 2.2.2 Patch available CNA
- bugsink (PyPI) Vendor— Affected before 2.2.2 Fixed in 2.2.2 Patch available GHSA-5x67-j5xg-c5gj
Remediation
- Fix · CNA bugsink (bugsink) Fixed in 2.2.2
- Fix · GHSA-5x67-j5xg-c5gj bugsink (PyPI) Fixed in 2.2.2 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-53954
- 2026-10-03 Alias added: GHSA-5x67-j5xg-c5gj
References
Other 5
- https://github.com/bugsink/bugsink/security/advisories/GHSA-5x67-j5xg-c5gj
- https://github.com/bugsink/bugsink/commit/1d0539fefcd1a796143d15d84053b1c0122ef8c7
- https://github.com/bugsink/bugsink/commit/8dca571b9e66c535ed4885465db820824e7c491a
- https://github.com/bugsink/bugsink/releases/tag/2.2.2
- https://github.com/bugsink/bugsink
More bugsink vulnerabilities
- TI-2026-22000 Bugsink is vulnerable to Stored XSS via Pygments fallback in stacktrace rendering CVSS 3.1CRITICAL 9.3
- TI-2025-39901 Bugsink vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU) CVSS 3.1HIGH 7.5
- TI-2025-39900 Bugsink vulnerable to unauthenticated remote DoS via crafted Brotli input CVSS 3.1HIGH 7.5
- TI-2025-34236 Bugsink is vulnerable to Path Traversal attacks via event_id in ingestion CVSS 4.0HIGH 7.2
- TI-2026-28977 Bugsink affected by authenticated arbitrary file write in artifactbundle/assemble CVSS 3.1HIGH 7.1
- TI-2026-32436 Bugsink: SSRF bypass in `validate_webhook_url` CVSS 3.1MEDIUM 4.3
Sources
- CVE-2026-53954 · CVE Program
- CVE-2026-53954 · NVD
- FIRST EPSS
- GHSA-5x67-j5xg-c5gj · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences