Bug 2502836 (CVE-2026-63090)

Summary:	CVE-2026-63090 ProFTPD: mod_sftp: heap buffer overflow via SFTP packet reassembly
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	Keywords:	Security
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Hardware:	All
OS:	Linux
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:	2502963, 2502964
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Description OSIDB Bzimport 2026-07-20 15:03:17 UTC

ProFTPD before 1.3.9c and 1.3.10rc3 contains a heap-based buffer overflow vulnerability in the mod_sftp module that allows authenticated low-privilege attackers to achieve arbitrary code execution by sending crafted SFTP packet fragments exceeding the 16 KB reassembly buffer in the fxp.c component. Attackers can supply oversized fragments to trigger an incorrectly conditioned reallocation, corrupt pool freelist metadata, overwrite the root_fs BSS global pointer to reference a fake filesystem struct, and redirect pr_fsio_stat() to system() via a crafted RENAME request.