CVE-2025-64509

HIGH
Published Nov 10, 2025 Modified Apr 15, 2026 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.

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CVSS v3.1 Score

7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-770 CWE-770

References

Frequently Asked Questions

What is CVE-2025-64509? +
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. It has a CVSS v3.1 base score of 7.5 (HIGH).
How severe is CVE-2025-64509? +
CVE-2025-64509 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
How do I check if I'm vulnerable to CVE-2025-64509? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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