High File handling

CVE-2026-35025 — ProFTPD ACL Bypass via /proc/self/root Path Prefix in RNFR

ProFTPD through 1.3.9b and 1.3.10rc2 contains an access control bypass vulnerability that allows authenticated FTP users to circumvent Directory ACL restrictions by prefixing paths with /proc/self/root in the RNFR command handler. Attackers can exploit the unresolved symlink components in dir_canonical_path() to cause dir_check() to perform lexical path comparisons that match no configured Directory block, enabling rename operations on files in DenyAll-protected directories and subsequent retrieval of those files. Mitigation: Sessions configured with DefaultRoot (chroot) are not affected, as chroot changes the directory to which /proc/self/root resolves.

Published Jun 24, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.5% (30-day exploitation probability)+6
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.51%

ahead of 42% of scored CVEs · Oct 15, 2026

Affects

Proftpd

Proftpd and 1 more

CVSS base

8.1

High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented mitigation — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Proftpd Proftpd, ProFTPD Project ProFTPD).
Apply the documented mitigations until a definitive fix is available.
Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Proftpd	Proftpd	≤ 1.3.9bversion 1.3.10-rc1version 1.3.10-rc2	Vulnerable	NIST National Vulnerability Database
ProFTPD Project	ProFTPD	≤ 1.3.9b≤ 1.3.10rc2	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.6	CVSS 4.0	High	—	—	disclosure@vulncheck.com via NIST National Vulnerability Database
8.6	CVSS 4.0	High	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP
8.1	CVSS 3.1	High	2.8	5.2	disclosure@vulncheck.com via NIST National Vulnerability Database
8.1	CVSS 3.1	High	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N (score shown at the top: disclosure@vulncheck.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-59 · Link Following

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.51%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Monitor file creation in web directories and paths with traversal sequences (../).

web/proxy/WAF logsnetwork IDS/IPSfile integrity (FIM)endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · proftpd project/proftpd
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 8.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jun 24, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

3 on the record

github.com/proftpd/proftpd/issues/2170
Issue Tracking, Mitigation, technical-description, NIST National Vulnerability Database
www.proftpd.org/
Product, Release Notes, product, NIST National Vulnerability Database
www.vulncheck.com/advisories/proftpd-acl-bypass-via-proc-self-root-path-prefix-in-rnfr
Third Party Advisory, third-party-advisory, NIST National Vulnerability Database

Elsewhere on this site

Proftpd
every CVE for this vendor

File handling
same class

CWE-59
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-63090 ProFTPD mod_sftp Heap Buffer Overflow via SFTP Packet Reassembly Jul 20, 2026
Medium CVE-2026-63091 ProFTPD mod_sftp Signed Integer Overflow via SCP Size-Record Parser Jul 20, 2026
Medium CVE-2026-53994 ProFTPD mod_sftp Heap Buffer Overflow via Unsigned Integer Underflow and Size Truncation Jul 18, 2026
High CVE-2026-44331 SQL Injection in Proftpd May 5, 2026
High CVE-2026-42167 SQL Injection in Proftpd Apr 28, 2026
High CVE-2021-47865 ProFTPD 1.3.7a - Remote Denial of Service Jan 21, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-35025 is "ProFTPD ACL Bypass via /proc/self/root Path Prefix in RNFR", rated High. It affects Proftpd (Proftpd); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.1 describes technical severity. EPSS 0.51% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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