SECURELYN

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 recommend…

Scores

9.2
CVSS 9.2 out of 10, critical severity.
0.5%
EPSS 0.5% chance of exploitation in the next 30 days.

The facts

Published
2 October 2026
Last changed
2 October 2026
NVD status
Deferred
Severity
Critical, CVSS 9.2 out of 10 (version 4.0)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R…
Weakness
Known exploited
Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
EPSS
0.5% chance of exploitation activity in the next 30 days (percentile 39).

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References