CVE record · CVE-2026-55971

Apache Thrift: C++ ZLIB heap buffer overflow (write) in THeaderTransport::untransform()

CVSS 9.3 CriticalCriticalEPSS 0.0098 · 62nd percentile

Critical, because:

CVSS score 9.3: 9.0 or more.

Published by the CVE Program (CNA: apache) at 27 Jul 2026, 11:11 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
Apache Software Foundation	Apache Thrift Package name: thrift https://conan.io/center	affected before 0.24.0 semver Other versions: unaffected

Identifiers: CVE-2026-55971
CNA: apache
Weakness (CWE): CWE-122
Tags: Apache Software Foundation Apache Thrift
Memory corruption
Published: 27 Jul 2026
Updated: 28 Jul 2026

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.3	Critical	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	CNA (apache)

CISA KEV Not listed.
EPSS 0.0098, the 62nd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the CVE Program, published 27 Jul 2026. New records show when each source confirmed them.

Sources

References from the CNA

lists.apache.org/thread/7v3jhgwfbmhx42424phydlnzb109g8b9 vendor-advisory
lists.apache.org/thread/xjs36m6kjxpmrmzwck636msg3nvoqnmx vendor-advisory

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.