CVE intelligence

CVE-2026-91135

Vulnerability intelligence

Published Oct 2, 2026Sources checked Oct 7, 2026

9.2CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-91135 and is rated Critical severity with a CVSS score of 9.2. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Oct 3, 2026

Release Notes

CISA KEVNot listedBased on the latest collected catalog

EPSS0.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-91135?

Heap-based buffer overflow vulnerability in Apache Thrift C++ THeaderTransport. When an application enables the ZLIB transform for the frames it sends, THeaderTransport::transform() copies the compressed frame into the write buffer without making sure it fits. Data that does not compress, such as content a remote peer supplied, grows under compression, so the copy writes past the end of the heap buffer by an amount that grows with the size of the frame, and for large frames it also reads past the end of the transform buffer. This issue affects Apache Thrift: before 0.25.0. Users are recommended to upgrade to version 0.25.0, which fixes the issue.

Source: NVD