CVE-2025-64509
Bugsink vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Bugsink vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)
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.
- Record
CVE-2025-64509- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2025-50819
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.
- Record
EUVD-2025-50819- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-rrx3-2x4g-mq2h
Bugsink is vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)
Impact
In affected versions, 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).
Patches
Patched in Bugsink 2.0.6
References
The vulnerability in this security advisory is similar to, but distinct from, another brotli-related problem in Bugsink:
https://github.com/bugsink/bugsink/security/advisories/GHSA-fc2v-vcwj-269v
- Record
GHSA-rrx3-2x4g-mq2h- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-64509- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSV
Bugsink vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)
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.
- Record
CVE-2025-64509- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVGHSA-rrx3-2x4g-mq2h
Bugsink is vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)
Impact
In affected versions, 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).
Patches
Patched in Bugsink 2.0.6
References
The vulnerability in this security advisory is similar to, but distinct from, another brotli-related problem in Bugsink:
https://github.com/bugsink/bugsink/security/advisories/GHSA-fc2v-vcwj-269v
- Record
GHSA-rrx3-2x4g-mq2h- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVPYSEC-2026-1227
Bugsink is vulnerable to unauthenticated remote DoS via crafted Brotli input (via CPU)
Impact
In affected versions, 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).
Patches
Patched in Bugsink 2.0.6
References
The vulnerability in this security advisory is similar to, but distinct from, another brotli-related problem in Bugsink:
https://github.com/bugsink/bugsink/security/advisories/GHSA-fc2v-vcwj-269v
- Record
PYSEC-2026-1227- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
bugsinkPyPI |
before 2.0.6 | 2.0.6 |
bugsinkPyPI |
before 2.0.6, plus listed versions 0.0.10.1.120.1.130.1.140.1.15 Show 41 moreShow less0.1.160.1.170.1.180.1.190.1.201.0.01.0.11.1.01.1.11.1.21.2.01.3.01.4.01.4.11.4.21.4.31.5.01.5.11.5.21.5.31.5.41.5.51.6.01.6.11.6.21.6.31.6.41.7.01.7.11.7.21.7.31.7.41.7.51.7.62.0.02.0.0a12.0.12.0.22.0.32.0.42.0.5 |
2.0.6 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-64509 is a high vulnerability (CVSS 7.5) in Bugsink, published November 10, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.34%, the 27th percentile. Fixed in bugsink 2.0.6.
References
github.com/bugsink/bugsink/security/advisories/GHSA-rrx3-2x4g-mq2h
nvd.nist.gov/vuln/detail/CVE-2025-64509
pypi.org/project/bugsink