High

CVE-2025-53896 — Kiteworks MFT is vulnerable to Insufficient Session Expiration

Kiteworks MFT orchestrates end-to-end file transfer workflows. Prior to version 9.1.0, a bug in Kiteworks MFT could cause under certain circumstances that a user's active session would not properly time out due to inactivity. This issue has been patched in version 9.1.0.

Published Nov 29, 2025 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

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 0.2% (30-day exploitation probability)+1
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

0.2%

ahead of 9% of scored CVEs · Oct 14, 2026

Affects

Accellion

Kiteworks Managed File Transfer and 1 more

CVSS base

8.1

High · 3 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 patch — 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 (Accellion Kiteworks Managed File Transfer, Kiteworks Security-advisories).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Accellion	Kiteworks Managed File Transfer	< 9.1.0	Vulnerable	NIST National Vulnerability Database
Kiteworks	Security-advisories	version < 9.1.0	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
8.1	CVSS 3.1	High	2.8	5.2	nvd@nist.gov via NIST National Vulnerability Database
7.1	CVSS 3.1	High	1.8	5.2	security-advisories@github.com via NIST National Vulnerability Database
7.1	CVSS 3.1	High	—	—	GitHub_M 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: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.1 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-613

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.20%

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).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · kiteworks/security-advisories
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
2025
CVE published
Nov 29, 2025 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

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

References

1 on the record

github.com/kiteworks/security-advisories/security/advisories/GHSA-23h2-3jj8-58hm
Patch, Third Party Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database

Elsewhere on this site

Accellion
every CVE for this vendor

CWE-613
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-24754 Kiteworks Secure Data Forms Vulnerable to Cross-site Scripting Jun 1, 2026
Medium CVE-2026-28272 Kiteworks Email Protection Gateway has a Cross-site Scripting vulnerability Feb 27, 2026
High CVE-2026-28270 Kiteworks Core has an Unrestricted Upload of File with Dangerous Type Feb 27, 2026
Medium CVE-2026-28271 Kiteworks Core is vulnerable to Server-Side Request Forgery (SSRF) Feb 27, 2026
High CVE-2026-28269 Kiteworks Core has an OS Command Injection Feb 26, 2026
High CVE-2025-53939 Kiteworks Core is vulnerable to Improper Input Validation Nov 29, 2025

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-2025-53896 is "Kiteworks MFT is vulnerable to Insufficient Session Expiration", rated High. It affects Kiteworks Managed File Transfer (Accellion); 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 0.20% 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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