CVE-2025-64509: Bugsink vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-11-10 · updated 2026-06-17
Weakness: CWE-770

Description

Bugsink is a self-hosted error tracking tool. In versions prior to 2.0.6, a specially crafted Brotli-compressed envelope can cause Bugsink to spend excessive CPU time in decompression, leading to denial of service. This can be done if the DSN is known, which it is in many common setups (JavaScript, Mobile Apps). The issue is patched in Bugsink 2.0.6. The vulnerability is similar to, but distinct from, another brotli-related problem in Bugsink, GHSA-fc2v-vcwj-269v/CVE-2025-64508.

Affected products

bugsink: before 2.0.6

References

https://github.com/bugsink/bugsink/security/advisories/GHSA-rrx3-2x4g-mq2h

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