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Response snapshot Oct 30, 2026, 17:01 UTC

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VulnerabilityCVE-2026-80463

Unbounded memory accumulation in the stream message reassembly path of Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to exhaust the memory of a server...

Unbounded memory accumulation in the stream message reassembly path of Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to exhaust the memory of a server (denial of service) by sending an endless sequence of continuation data frames.

At a glance

Exploited
Not known
Severity
7.5 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-80463 (opens a new tab)

What happened

Unbounded memory accumulation in the stream message reassembly path of Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to exhaust the memory of a server (denial of service) by sending an endless sequence of continuation data frames.

Root Cause: The streaming RPC protocol bounds every single data frame by max_body_size, but a fragmented stream message accumulates continuation frames into one buffer (_pending_buf) without any limit on the accumulated size. A malicious peer that can open a stream can therefore keep sending continuation frames to make the receiver accumulate an arbitrarily large in-memory message.

Since the default flow-control settings (socket_max_streams_unconsumed_bytes=0) do not throttle the sending rate, the receiver's memory grows until the process runs out of memory and crashes or becomes unavailable.

Affected Scenarios: Services that accept streams from untrusted clients (for example using brpc::StreamAccept or brpc::StreamCreate with the built-in streaming protocol) are affected.

Continue reading

How to Fix: (Choose one of the following options) 1. Upgrade bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3489

Note: The fix limits the accumulated payload of a fragmented stream message to max_body_size (default 64MB). When the accumulated payload exceeds the limit, the pending fragments are released and the stream is closed with error EMSGSIZE. After applying the fix, legitimate fragmented stream messages larger than max_body_size will be rejected; you can adjust the gflag max_body_size to change the limit.

Scores and how they were measured

CVSS base severity

7.5

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Sources

  1. Primary source

    NVD CVE-2026-80463 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 30). Unbounded memory accumulation in the stream message reassembly path of Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to exhaust the memory of a server... (CVE-2026-80463). https://kevwire.com/record/CVE-2026-80463

MLA

"Unbounded memory accumulation in the stream message reassembly path of Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to exhaust the memory of a server... (CVE-2026-80463)." KEVWire, 30 Oct. 2026, kevwire.com/record/CVE-2026-80463.

Chicago

KEVWire. "Unbounded memory accumulation in the stream message reassembly path of Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to exhaust the memory of a server... (CVE-2026-80463)." Last modified October 30, 2026. https://kevwire.com/record/CVE-2026-80463.

Evidence summary (plain text)

Unbounded memory accumulation in the stream message reassembly path of Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to exhaust the memory of a server... (Oct 21, 2026).
Unbounded memory accumulation in the stream message reassembly path of Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to exhaust the memory of a server (denial of service) by sending an endless sequence of continuation data frames.

Root Cause:
The streaming RPC protocol bounds every single data frame by max_body_size, but a fragmented stream message accumulates continuation frames into one buffer (_pending_buf) without any limit on the accumulated size.
CVSS 7.5 (version 3.1; evidence as of Oct 30, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-80463).
Sources:
NVD CVE-2026-80463: https://nvd.nist.gov/vuln/detail/CVE-2026-80463
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-30T14:50:59.566Z&lastModEndDate=2026-10-30T16:25:56.397Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-30T13:52:33.301Z&lastModEndDate=2026-10-30T15:50:56.559Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2026-80463.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 30, 2026, 16:25 UTC. Ingestion is not an independent editorial investigation.

NVD status: Deferred. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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Record details

Record detail