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Response snapshot Oct 30, 2026, 19:11 UTC

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VulnerabilityCVE-2026-78334

Missing authentication in the streaming RPC path of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to bypass server authentication and inject or deliver...

Missing authentication in the streaming RPC path of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to bypass server authentication and inject or deliver streaming frames, when a server is configured with an Authenticator.

At a glance

Exploited
Not known
Severity
9.1 Critical (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-2026-78334 (opens a new tab)

What happened

Missing authentication in the streaming RPC path of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to bypass server authentication and inject or deliver streaming frames, when a server is configured with an Authenticator.

Root Cause: When authentication is configured, streaming RPC frames are consumed directly by the streaming parser (ParseStreamingMessage) and never pass through InputMessenger's authentication hook, so an unauthenticated peer can exchange frames without being authenticated.

In addition, a server-accepted stream is bound lazily to the first frame that happens to carry its id, so a stream could accept a frame carrying its id from a socket other than the socket that created the stream.

Affected Scenarios: A bRPC server configured with authentication that serves streaming RPC from an untrusted network, or a deployment where a foreign connection can impersonate a stream by id, can be made to accept unauthorized streaming frames.

Continue reading

How to Fix: Upgrade bRPC to 1.18.0, which fixes this issue, or apply the patch in PR https://github.com/apache/brpc/pull/3481.

Note: The fix rejects streaming frames on server sockets when configured authentication has not completed, and keeps server-accepted streams bound to the socket of their creating RPC and rejects frames arriving from another socket. Authenticated streaming RPC behavior and the wire format are unchanged; only unauthenticated or foreign-socket frames are now rejected.

Scores and how they were measured

CVSS base severity

9.1

Version 3.1As of

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/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-2026-78334 (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). Missing authentication in the streaming RPC path of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to bypass server authentication and inject or deliver... (CVE-2026-78334). https://kevwire.com/record/CVE-2026-78334

MLA

"Missing authentication in the streaming RPC path of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to bypass server authentication and inject or deliver... (CVE-2026-78334)." KEVWire, 30 Oct. 2026, kevwire.com/record/CVE-2026-78334.

Chicago

KEVWire. "Missing authentication in the streaming RPC path of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to bypass server authentication and inject or deliver... (CVE-2026-78334)." Last modified October 30, 2026. https://kevwire.com/record/CVE-2026-78334.

Evidence summary (plain text)

Missing authentication in the streaming RPC path of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to bypass server authentication and inject or deliver... (Oct 21, 2026).
Missing authentication in the streaming RPC path of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to bypass server authentication and inject or deliver streaming frames, when a server is configured with an Authenticator.

Root Cause:
When authentication is configured, streaming RPC frames are consumed directly by the streaming parser (ParseStreamingMessage) and never pass through InputMessenger's authentication hook, so an unauthenticated peer can exchange frames without being authenticated.
CVSS 9.1 (version 3.1; evidence as of Oct 30, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-78334).
Sources:
NVD CVE-2026-78334: https://nvd.nist.gov/vuln/detail/CVE-2026-78334
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-2026-78334.
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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