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Response snapshot Oct 30, 2026, 19:11 UTC

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VulnerabilityCVE-2026-79704

An out-of-bounds read vulnerability exists in the streaming RPC client of Apache bRPC (versions 1.11.0 through  1.17.0) on all platforms.

An out-of-bounds read vulnerability exists in the streaming RPC client of Apache bRPC (versions 1.11.0 through  1.17.0) on all platforms. A client that creates multiple streams in a single RPC expects the server response to carry exactly one extra_stream_id for every additional stream.

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-2026-79704 (opens a new tab)

What happened

An out-of-bounds read vulnerability exists in the streaming RPC client of Apache bRPC (versions 1.11.0 through  1.17.0) on all platforms. A client that creates multiple streams in a single RPC expects the server response to carry exactly one extra_stream_id for every additional stream.

The response handling path indexed the returned identifiers using the locally created stream count without first validating the size of the returned list, so a malicious or compromised server (or an on-path attacker) can trigger an out-of-bounds read in the client by returning a malformed StreamSettings response with fewer extra_stream_ids than expected.

This may crash the client process (denial of service) or leak unintended memory contents into subsequent stream handling; surplus identifiers have no valid client-stream mapping and are processed inconsistently.

Root Cause: Since bRPC 1.11.0, a client can create multiple streams in one RPC via batch StreamCreate. The expected behavior is that the server response must return exactly (N-1) extra_stream_ids, where N is the number of locally created streams.

Continue reading

In Controller::HandleStreamConnection, the response path reads extra_stream_ids[i-1] for each additional local stream without first comparing the returned list size with (N-1). If the server returns fewer identifiers, the read runs past the end of the returned list (out-of-bounds read); if it returns more, the surplus identifiers have no corresponding client-side stream.

Affected Scenarios: A bRPC client using multi-stream RPC (creating more than one stream in a single RPC) that connects to an untrusted, malicious, or compromised server or to a server reached through an untrusted network path. The server sends a malformed StreamSettings response to trigger the issue.

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/3485

Note: The fix makes the client reject responses whose extra_stream_ids count does not exactly match the number of additional client streams. Such mismatched responses now fail the RPC with ERESPONSE and go through the existing stream cleanup path, instead of being partially processed.

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-2026-79704 (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

  4. 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). An out-of-bounds read vulnerability exists in the streaming RPC client of Apache bRPC (versions 1.11.0 through  1.17.0) on all platforms. (CVE-2026-79704). https://kevwire.com/record/CVE-2026-79704

MLA

"An out-of-bounds read vulnerability exists in the streaming RPC client of Apache bRPC (versions 1.11.0 through  1.17.0) on all platforms. (CVE-2026-79704)." KEVWire, 30 Oct. 2026, kevwire.com/record/CVE-2026-79704.

Chicago

KEVWire. "An out-of-bounds read vulnerability exists in the streaming RPC client of Apache bRPC (versions 1.11.0 through  1.17.0) on all platforms. (CVE-2026-79704)." Last modified October 30, 2026. https://kevwire.com/record/CVE-2026-79704.

Evidence summary (plain text)

An out-of-bounds read vulnerability exists in the streaming RPC client of Apache bRPC (versions 1.11.0 through  1.17.0) on all platforms. (Oct 21, 2026).
An out-of-bounds read vulnerability exists in the streaming RPC client of Apache bRPC (versions 1.11.0 through  1.17.0) on all platforms. A client that creates multiple streams in a single RPC expects the server response to carry exactly one extra_stream_id for every additional stream.
CVSS 7.5 (version 3.1; evidence as of Oct 30, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-79704).
Sources:
NVD CVE-2026-79704: https://nvd.nist.gov/vuln/detail/CVE-2026-79704
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-30T17:10:58.916Z&lastModEndDate=2026-10-30T18:40:56.214Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-30T16:36:00.636Z&lastModEndDate=2026-10-30T18:10:56.487Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-30T16:01:04.448Z&lastModEndDate=2026-10-30T17:35:57.241Z&resultsPerPage=500&startIndex=0
Record ID: CVE-2026-79704.
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, 18:40 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

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