CVE-2026-53954 Bugsink: DOS using large numbers of event tags
Attackers with valid project DSNs can cause denial of service by submitting excessive event tags, delaying ingestion in Bugsink.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53954?
CVE-2026-53954 is a medium-severity denial of service vulnerability in bugsink, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-400
Which versions are affected by CVE-2026-53954?
3 open source packages ship an affected version, including bugsink.
| Package | Affected | Fixed in |
|---|---|---|
bugsink PyPI | All versions | 2.2.2 |
bugsink PyPI | All versions | 2.2.2 |
bugsink PyPI | All versions | 2.2.2 |
How do I fix CVE-2026-53954?
Upgrade bugsink to 2.2.2 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-53954 being exploited?
There is no known exploitation of CVE-2026-53954 in the wild and no public exploit code.
Sources
Also known as GHSA-5x67-j5xg-c5gj, PYSEC-2026-2403.