Vulnerability Description
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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Proftpd | Proftpd | < 1.3.9c |
Related Weaknesses (CWE)
References
- https://github.com/proftpd/proftpd/blob/master/RELEASE_NOTESRelease Notes
- https://github.com/proftpd/proftpd/commit/4ee8701bcf425f11b3b2116e634ff3e655d918Patch
- https://github.com/proftpd/proftpd/issues/2190Issue Tracking
- https://github.com/proftpd/proftpd/releases/tag/v1.3.10rc3-3ProductRelease Notes
- https://github.com/proftpd/proftpd/releases/tag/v1.3.9cProductRelease Notes
- https://www.vulncheck.com/advisories/proftpd-mod-sftp-heap-buffer-overflow-via-sThird Party AdvisoryPatchRelease Notes
FAQ
What is CVE-2026-63090?
CVE-2026-63090 is a vulnerability with a CVSS score of 8.8 (HIGH). 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 ...
How severe is CVE-2026-63090?
CVE-2026-63090 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-63090?
Check the references section above for vendor advisories and patch information. Affected products include: Proftpd Proftpd.