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Response snapshot Oct 30, 2026, 19:11 UTC

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VulnerabilityCVE-2026-78066

Resource exhaustion in Apache bRPC (version < 1.18.0) on all platforms: multiple parsers that accept wire-controlled input bound no limit on the sizes declared by the client or on...

Resource exhaustion in Apache bRPC (version < 1.18.0) on all platforms: multiple parsers that accept wire-controlled input bound no limit on the sizes declared by the client or on decompressed output, which attackers can use to drive disproportionate memory use and crash the process.

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-2026-78066 (opens a new tab)

What happened

Resource exhaustion in Apache bRPC (version < 1.18.0) on all platforms: multiple parsers that accept wire-controlled input bound no limit on the sizes declared by the client or on decompressed output, which attackers can use to drive disproportionate memory use and crash the process.

Root Cause: 1) The gzip/zlib/snappy decompressors enforce no output limit: -max_body_size is checked against the compressed bytes only, so a cap-compliant body (e.g. 64 MiB) can decompress to tens of GiB. 2) The AMF string readers allocate the declared length before the bytes are actually available.

3) RTMP chunk headers may re-declare a message length mid-stream; the declared length was never bounded and the partial reassembly buffer kept growing. 4) The sofa-pbrpc parser does not bound meta_size. 5) mcpack2pb trusts wire-declared item counts for Reserve() and a string value_size of 0 underflows the buffer size, aborting the process.

Affected Scenarios: Any bRPC service accepting gzip/zlib/snappy-compressed bodies or rtmp, sofa-pbrpc, or mcpack2pb messages from untrusted clients.

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/3476

Note: After the fix, requests whose decompressed size, RTMP message length, or mcpack declared count exceed the new limits are rejected. Operators who legitimately need larger values can raise the corresponding flag (-max_decompressed_body_size, max_body_size).

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-2026-78066 (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). Resource exhaustion in Apache bRPC (version < 1.18.0) on all platforms: multiple parsers that accept wire-controlled input bound no limit on the sizes declared by the client or on... (CVE-2026-78066). https://kevwire.com/record/CVE-2026-78066

MLA

"Resource exhaustion in Apache bRPC (version < 1.18.0) on all platforms: multiple parsers that accept wire-controlled input bound no limit on the sizes declared by the client or on... (CVE-2026-78066)." KEVWire, 30 Oct. 2026, kevwire.com/record/CVE-2026-78066.

Chicago

KEVWire. "Resource exhaustion in Apache bRPC (version < 1.18.0) on all platforms: multiple parsers that accept wire-controlled input bound no limit on the sizes declared by the client or on... (CVE-2026-78066)." Last modified October 30, 2026. https://kevwire.com/record/CVE-2026-78066.

Evidence summary (plain text)

Resource exhaustion in Apache bRPC (version < 1.18.0) on all platforms: multiple parsers that accept wire-controlled input bound no limit on the sizes declared by the client or on... (Oct 21, 2026).
Resource exhaustion in Apache bRPC (version < 1.18.0) on all platforms: multiple parsers that accept wire-controlled input bound no limit on the sizes declared by the client or on decompressed output, which attackers can use to drive disproportionate memory use and crash the process.

Root Cause:
1) The gzip/zlib/snappy decompressors enforce no output limit: -max_body_size is checked against the compressed bytes only, so a cap-compliant body (e.g. 64 MiB) can decompress to tens of GiB.
2) The AMF string readers allocate the declared length before the bytes are actually available.
CVSS 7.5 (version 3.1; evidence as of Oct 30, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-78066).
Sources:
NVD CVE-2026-78066: https://nvd.nist.gov/vuln/detail/CVE-2026-78066
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-2026-78066.
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

Record detail