CVE-2025-64508: high-severity vulnerability in bugsink
Bugsink vulnerable to unauthenticated remote DoS via crafted Brotli input
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.5%
Bugsink is a self-hosted error tracking tool. In versions prior to 2.0.5, brotli "bombs" (highly compressed brotli streams, such as many zeros) can be sent to the server. Since the server will attempt to decompress these streams before applying various maximums, this can lead to exhaustion of the available memory and thus a 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 version `2.0.5`. The vulnerability is similar to, but distinct from, another brotli-related problem in Bugsink, GHSA-rrx3-2x4g-mq2h/CVE-2025-64509.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
bugsink · bugsinkRelated CVEs — bugsink
In the same product, most dangerous first.
CVE-2025-54433HIGHBugsink is vulnerable to Path Traversal attacks via event_id in ingestionEPSS 0.7%CVE-2026-53954MEDIUMBugsink: DOS using large numbers of event tagsEPSS 0.6%CVE-2025-64509HIGHBugsink vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)EPSS 0.3%CVE-2026-27614CRITICALBugsink is vulnerable to Stored XSS via Pygments fallback in stacktrace renderingEPSS 0.3%CVE-2026-40162HIGHBugsink affected by authenticated arbitrary file write in artifactbundle/assembleEPSS 0.3%CVE-2026-44502MEDIUMBugsink: SSRF bypass in `validate_webhook_url`EPSS 0.3%
References
https://github.com/bugsink/bugsink/commit/3f65544aab3ad5303d97009136640de97b0676a5https://github.com/bugsink/bugsink/pull/266https://github.com/bugsink/bugsink/security/advisories/GHSA-fc2v-vcwj-269vhttps://github.com/google/brotli/commit/67d78bc41db1a0d03f2e763497748f2f69946627https://github.com/google/brotli/issues/1327https://github.com/google/brotli/issues/1375https://github.com/google/brotli/pull/1234https://github.com/google/brotli/releases/tag/v1.2.0