CVE-2026-66858Network attack vectorHinoki check available

Service crash via unbounded unknown-field recursion

Published Oct 2, 2026 · Updated Oct 2, 2026

Uncontrolled recursion in Apache Thrift before 0.25.0 allows remote attackers to crash services via deeply nested unknown RPC fields. The affected bindings' protocol skip routines recurse through unknown nested fields without applying the binding's recursion limit, exhausting the call stack. Exposure requires a service to decode attacker-controlled messages with an affected binding; pure-Python protocols are not affected.

CVSS severityUnavailable
Unscored
EPSS probability0.26%
Next 30 days · Oct 20, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Uncontrolled recursion in Apache Thrift before 0.25.0 allows remote attackers to crash services via deeply nested unknown RPC fields. The affected bindings' protocol skip routines recurse through unknown nested fields without applying the binding's recursion limit, exhausting the call stack. Exposure requires a service to decode attacker-controlled messages with an affected binding; pure-Python protocols are not affected.

The record

CVE
CVE-2026-66858
Published
Oct 2, 2026
Updated
Oct 2, 2026
Vendor
Apache Software Foundation
Product
Apache Thrift
Classifications
T1499.004
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 2, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.25.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

Apache Software Foundation · Apache Thriftversion=0 <0.25.0

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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