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TI-2026-45041 Aliases CVE-2026-63091GHSA-gqm5-f386-9r92

ProFTPD mod_sftp Signed Integer Overflow via SCP Size-Record Parser

Priority LOW 32CWE-126Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-126 and the CVSS impact.

Summary

ProFTPD before 1.3.9c and 1.3.10rc3 contains a signed integer overflow vulnerability in the mod_sftp module's SCP size-record parser that allows authenticated low-privilege attackers to bypass ASLR by sending a crafted file size value of UINT64_MAX, which results in a negative off_t value. Attackers can exploit the subsequent conversion to uint32_t, causing an approximately 4 GB requested read length and forcing the server to read beyond the end of the SSH channel data and write overread process memory into the uploaded file. In tested configurations, the disclosed data contains libc, libcrypto, and PIE pointers sufficient to derive their randomized base addresses, thereby bypassing ASLR and enabling reliable exploitation of memory corruption vulnerabilities in the same process.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00525 44th percentileScored 2026-11-07
Fix Fixed proftpd (proftpd): 1.3.9c, 1.3.10rc3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ProFTPDproftpdbefore 1.3.9c; 1.3.10rc1 to before 1.3.10rc31.3.9c, 1.3.10rc3Patch availableCNA
  • proftpd VendorProFTPD Affected before 1.3.9c; 1.3.10rc1 to before 1.3.10rc3 Fixed in 1.3.9c, 1.3.10rc3 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:proftpd:proftpd:*:*:*:*:*:*:*:*before 1.3.9cVulnerableProFTPD
cpe:2.3:a:proftpd:proftpd:1.3.10:rc1:*:*:*:*:*:*1.3.10 rc1VulnerableProFTPD
cpe:2.3:a:proftpd:proftpd:1.3.10:rc2:*:*:*:*:*:*1.3.10 rc2VulnerableProFTPD
  • cpe:2.3:a:proftpd:proftpd:*:*:*:*:*:*:*:* Versions before 1.3.9c Vulnerable ·ProFTPD
  • cpe:2.3:a:proftpd:proftpd:1.3.10:rc1:*:*:*:*:*:* Versions 1.3.10 rc1 Vulnerable ·ProFTPD
  • cpe:2.3:a:proftpd:proftpd:1.3.10:rc2:*:*:*:*:*:* Versions 1.3.10 rc2 Vulnerable ·ProFTPD

Remediation

  • Fix · CNA proftpd (proftpd) Fixed in 1.3.9c, 1.3.10rc3

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    proftpd 1.3.10rc3, 1.3.9c

    2 records Highest priority Priority MEDIUM 1 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-45040 ProFTPD mod_sftp Heap Buffer Overflow via SFTP Packet ReassemblyPriority MEDIUM 41
    Show all 2 records →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63091
  2. 2026-10-03 Alias added: GHSA-gqm5-f386-9r92

References

Patch 4

Other 1

  • TI-2015-02923 Access control flaw in ProFTPD mod_copy allows arbitrary file access KEVCVSS 3.1CRITICAL 10.0
  • TI-2010-03974 Multiple stack-based buffer overflows in the pr_netio_telnet_gets function in netio.c in… CVSS 2.0HIGH 10.0
  • TI-2010-05061 ProFTPD 1.3.3c Backdoor Command Execution CVSS 4.0CRITICAL 9.3
  • TI-2019-09597 An arbitrary file copy vulnerability in mod_copy in ProFTPD up to 1.3.5b allows for… CVSS 3.1CRITICAL 9.8
  • TI-2026-30493 SQL injection in ProFTPD CVSS 3.1HIGH 8.1
  • TI-2023-26623 The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6… CVSS 3.1MEDIUM 5.9
See all 32 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences