VulnTideExploited vulnerabilities, by vendor. Data as of .
Not in CISA KEVPublished EPSS 0.2% probability of exploitation in 30 daysFound by AI: Anthropic (Claude)
Apache

CVE-2026-78066: Apache bRPC: Resource Exhaustion via Unbounded Decompression and Unvalidated Wire-Declared Sizes

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?
0.2%

EPSS score, percentile 5.6 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?
Not scored

The CVE record carries no CVSS score.

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

  • before 1.18.0

Versions by product

Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.

What to do

Advisories and patches

This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Apache Software Foundation Apache bRPC
StatusVersions
Affectedbefore 1.18.0

Versions not listed are: unaffected.

Source: CVE List, as of . About the data.

About this vulnerability

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…

Summary: CVE record, as of .

  • CISA has not added CVE-2026-78066 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
  • The CVE record was published on 21 Oct 2026.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.2% (percentile 5.6), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
  • The credits in the CVE record name Anthropic (Claude) as finder.

Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.

Description

Apache bRPC: Resource Exhaustion via Unbounded Decompression and Unvalidated Wire-Declared Sizes

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. 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).

Source: CVE List, as of . About the data.

Weakness

CWE-770
  • CWE-770: Allocation of Resources Without Limits or Throttling

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.

Timeline

DateEvent
CVE record published

Known exploited Apache vulnerabilities

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  • CVE-2024-38475: Apache HTTP Server Improper Escaping of Output Vulnerability (added )
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