---
title: "CVE-2026-56386: Apache bRPC - Denial of Service"
description: "Apache bRPC < 1.18.0 contains an integer underflow and out-of-bounds read caused by improper handling of zero-length padded HTTP/2 DATA frames, letting unauthenticated remote attackers cause denial of service by sending malformed frames."
url: https://panop.io/threat-heartbeat/CVE-2026-56386/
---

# CVE-2026-56386 Apache bRPC - Denial of Service

Apache bRPC < 1.18.0 contains an integer underflow and out-of-bounds read caused by improper handling of zero-length padded HTTP/2 DATA frames, letting unauthenticated remote attackers cause denial of service by sending malformed frames.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-56386)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

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

Published

21 October 2026

Updated

22 October 2026

Weakness

[CWE-125](https://cwe.mitre.org/data/definitions/125.html)

## Vendor fix

Upgrade Apache bRPC to version 1.18.0 or apply the patch at https://github.com/apache/brpc/pull/3325.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-56386](https://nvd.nist.gov/vuln/detail/CVE-2026-56386)
- [https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb](https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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