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Vulnerabilities

Security research · CVE-2026-80463

Apache bRPC: Unbounded Memory Accumulation in Stream Message Reassembly

Published Oct 21, 2026 · catalog updated Oct 21, 2026 · Apache Software Foundation Apache bRPC

Last checked Oct 29, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-80463. EPSS is 0.20%. Act only if a listed version of Apache Software Foundation Apache bRPC is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.20%
Remediation
Version ranges on file
Affected products
stated named in the record · vendor Apache Software Foundation Apache bRPC

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. 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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • stated named in the record< 1.18.0
  • vendor Apache Software Foundation Apache bRPCversion unspecified

How to fix CVE-2026-80463

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-80463. EPSS is 0.20%. Act only if a listed version of Apache Software Foundation Apache bRPC is installed.

Which versions are affected?

Compare what you have installed with named in the record < 1.18.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-770: Allocation of Resources Without Limits or Throttling. EPSS 0.20%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 21, 2026 · NIST NVD

    Detected

    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 continuatio

Sources

  • CVE.orgVulnerability recordCVE-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 (denial of service) by sending an endless sequence of continuation data frames. Root Cause: The streami

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-80463

    30-day exploitation probability 0.20%

    first.org
  • NIST NVDVulnerability recordCVE-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 (denial of service) by sending an endless sequence of continuation data frames. Root Cause: The stream

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 29, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 23, 2026
  • CVE.orgOct 21, 2026
  • NIST NVDOct 21, 2026