CVE-2026-20018
CVE-2026-20018 is a medium-severity vulnerability with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-27.
Key facts
- Severity: Medium (CVSS 3.x base score 5.9)
- EPSS exploit prediction: 0% (34th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-9456
- Weakness: CWE-27
- Published:
- Last modified:
Description
A vulnerability in the sftunnel functionality of Cisco Secure Firewall Management Center (FMC) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrative privileges to write arbitrary files as root on the underlying operating system. This vulnerability is due to insufficient validation of the directory path during file synchronization. An attacker could exploit this vulnerability by crafting a directory path outside of the expected file location. A successful exploit could allow the attacker to create or replace any file on the underlying operating system.
Frequently asked questions
- What is CVE-2026-20018?
- A vulnerability in the sftunnel functionality of Cisco Secure Firewall Management Center (FMC) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrative privileges to write arbitrary files as root on the underlying operating system. This vulnerability is due to insufficient validation of the directory path during file synchronization. An attacker could exploit this vulnerability by crafting a directory path outside of the expected file location. A successful exploit could allow the attacker to create or replace any file on the underlying operating system.
- How severe is CVE-2026-20018?
- CVE-2026-20018 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
- Is CVE-2026-20018 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-20018?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-20018 have an EU (EUVD) identifier?
- Yes. CVE-2026-20018 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9456.
- When was CVE-2026-20018 published?
- CVE-2026-20018 was published on 2026-03-04 and last updated on 2026-06-17.
References
Other CWE-27 vulnerabilities
- CVE-2024-21896 — Critical (CVSS 9.8): The permission model protects itself against path traversal attacks by calling path.resolve() on any paths given by the…
- CVE-2025-10438 — High (CVSS 8.6): Path Traversal: 'dir/../../filename' vulnerability in Yordam Information Technology Consulting Education and Electrical…
- CVE-2025-58761 — High (CVSS 8.6): Tautulli is a Python based monitoring and tracking tool for Plex Media Server. The `real_pms_image_proxy` endpoint in…
- CVE-2024-24809 — High (CVSS 8.5): Traccar is an open source GPS tracking system. Versions prior to 6.0 are vulnerable to path traversal and unrestricted…
- CVE-2024-43658 — High (CVSS 7.2): Patch traversal, External Control of File Name or Path vulnerability in Iocharger Home allows deletion of arbitrary…
- CVE-2023-20090 — Medium (CVSS 6.7): A vulnerability in Cisco TelePresence CE and RoomOS could allow an authenticated, local attacker to elevate privileges…