Is CVE-2026-66858 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-66858 being exploited in the wild.

How severe is CVE-2026-66858?

Informational severity, published 2 October 2026.

Which products and versions are affected?

Apache Thrift before 0.25.0; Apache Thrift PHP library before 0.25.0; Apache Thrift Python C++ accelerator before 0.25.0.

Is there a fix for CVE-2026-66858?

Yes: fixed in 0.25.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-66858 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-66858?

Check whether you run Apache Thrift, Apache Thrift PHP library or Apache Thrift Python C++ accelerator at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-66858: Apache Thrift stack overflow in protocol skip routine

CVE-2026-66858 · Severity: info · Published 2026-10-02

Apache Thrift's protocol skip routines in several language bindings fail to enforce recursion limits, allowing deeply nested unknown fields in a message to exhaust the stack and crash the application. This affects applications using Python C++ accelerator, PHP, Perl, Lua, Smalltalk, and OCaml bindings, causing denial of service from a remote attacker sending a specially crafted message.

Technologies: Apache Thrift. Vendors: Apache.

Quick answers

Is CVE-2026-66858 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-66858 being exploited in the wild.
How severe is CVE-2026-66858?: Informational severity, published 2 October 2026.
Which products and versions are affected?: Apache Thrift before 0.25.0; Apache Thrift PHP library before 0.25.0; Apache Thrift Python C++ accelerator before 0.25.0.
Is there a fix for CVE-2026-66858?: Yes: fixed in 0.25.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-66858 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-66858?: Check whether you run Apache Thrift, Apache Thrift PHP library or Apache Thrift Python C++ accelerator at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 0.25.0

Technical details

The protocol skip routine does not apply the binding's configured recursion limit when processing nested fields, allowing stack exhaustion via deeply nested message structures. This affects the Python C++ accelerator, PHP library and thrift_protocol extension, and Perl, Lua, Smalltalk, and OCaml libraries. An attacker can trigger a stack overflow and application crash by sending a network message with excessive field nesting, no authentication required.

Affected products

Apache Thrift before 0.25.0
Apache Thrift Python C++ accelerator before 0.25.0
Apache Thrift PHP library before 0.25.0

Timeline

2026-10-02: disclosed

References

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