CVE-2026-79704 Vulnerability Analysis & Exploit Details

CVE-2026-79704
Vulnerability Scoring

Analysis In Progress
Analysis In Progress

Attack Complexity Details

  • Attack Complexity:
    Attack Complexity Analysis In Progress
  • Attack Vector:
    Attack Vector Under Analysis
  • Privileges Required: None
    No authentication is required for exploitation.
  • Scope:
    Impact is confined to the initially vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2026-79704 Details

Status: Deferred

Last updated: 🕗 26 Oct 2026, 20:10 UTC
Originally published on: 🕛 21 Oct 2026, 12:17 UTC

Time between publication and last update: 5 days

CVSS Release:

CVE-2026-79704 Vulnerability Summary

CVE-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. 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. 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.

Assessing the Risk of CVE-2026-79704

Access Complexity Graph

The exploitability of CVE-2026-79704 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2026-79704

No exploitability data is available for CVE-2026-79704.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2026-79704, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2026-79704, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2026-79704 does not compromise confidentiality.
  • Integrity: None
    CVE-2026-79704 does not impact data integrity.
  • Availability: None
    CVE-2026-79704 does not affect system availability.

CVE-2026-79704 References

External References

CWE Common Weakness Enumeration

CWE-125

CAPEC Common Attack Pattern Enumeration and Classification

  • Overread Buffers CAPEC-540 An adversary attacks a target by providing input that causes an application to read beyond the boundary of a defined buffer. This typically occurs when a value influencing where to start or stop reading is set to reflect positions outside of the valid memory location of the buffer. This type of attack may result in exposure of sensitive information, a system crash, or arbitrary code execution.

Protect Your Infrastructure against CVE-2026-79704: Combat Critical CVE Threats

Stay updated with real-time CVE vulnerabilities and take action to secure your systems. Enhance your cybersecurity posture with the latest threat intelligence and mitigation techniques. Develop the skills necessary to defend against CVEs and secure critical infrastructures. Join the top cybersecurity professionals safeguarding today's infrastructures.

Other 5 Recently Published CVEs Vulnerabilities

  • CVE-2026-117472 – Psono Server CE && EE versions 4.0.33 through 7.2.3 compared the request path for the bulk-secret-read endpoint with a hard-coded unprefixed path. ...
  • CVE-2026-117471 – Psono Server CE && EE versions 0.1.0 through 7.2.3 accepted a user-controlled host when configuring a personal Duo device and passed it to the Duo ...
  • CVE-2026-117470 – Psono Server CE & EE versions 3.1.0 through 7.2.3 did not consume a stored WebAuthn challenge after assertion verification. An unauthenticated remo...
  • CVE-2026-117469 – Psono Server (CE & EE) versions 1.0.0 through 7.2.3 did not enforce the direction of file-transfer credentials on file-repository operations. An au...
  • CVE-2026-117468 – Psono Server versions 5.3.5 through 7.2.3 used a permission class that did not enforce token write scope when claiming a device code. An authentica...