A buffer overflow, as described in CVE-2020-8927, exists in the embedded Brotli library. Versions of IO::Compress::Brotli prior to 0.007 included a version of the brotli library prior to version 1.0.8, where an attacker controlling the input length of a "one-shot" decompression request to a script can trigger a crash, which happens when copying over chunks of data larger than 2 GiB. It is recommended to update your IO::Compress::Brotli module to 0.007 or later. If one cannot update, we recommend to use the "streaming" API as opposed to the "one-shot" API, and impose chunk size limits.
CVE-2020-36846
CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2025-05-30. NVD baseline CVSS 9.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.8Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.8
- EG Score
- 9.8(medium)
- EPSS
- 41.3%
- KEV
- Not listed
Published
May 30, 2025
Last Modified
April 15, 2026
Advisory Details (4)
Auto-updated May 3, 2026🔬 Proof of concept available. Patch available. Sources: github.
generic
perl-IO-Compress-Brotli/Changes at 8b44c83b23bb4658179e1494af4b725a1bc476bc · timlegge/perl-IO-Compress-Brotli · GitHub
https://github.com/timlegge/perl-IO-Compress-Brotli/blob/8b44c83b23bb4658179e1494af4b725a1bc476bc/Changes#L52generic🟡 PoC Available
Update by eustas · Pull Request #826 · google/brotli · GitHub
https://github.com/google/brotli/pull/826generic
Update (#826) · google/brotli@223d80c · GitHub
https://github.com/google/brotli/commit/223d80cfbec8fd346e32906c732c8ede21f0cea6github Patch Available
Integer overflow in the bundled Brotli C library · CVE-2020-8927 · GitHub Advisory Database · GitHub
https://github.com/advisories/GHSA-5v8v-66v8-mwm7Frequently asked(5)
What is CVE-2020-36846?
CVE-2020-36846 is a critical vulnerability published on May 30, 2025. A buffer overflow, as described in CVE-2020-8927, exists in the embedded Brotli library. Versions of IO::Compress::Brotli prior to 0.007 included a version of the brotli library prior to version 1.0.8, where an attacker controlling the input length of a "one-shot" decompression request to a script…
When was CVE-2020-36846 disclosed?
CVE-2020-36846 was first published in the National Vulnerability Database on May 30, 2025, with the most recent update on April 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-36846 actively exploited?
CVE-2020-36846 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 41.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2020-36846?
CVE-2020-36846 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2020-36846?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-36846, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
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