CVE-2026-20262
CVE-2026-20262 is a security flaw in Cisco Catalyst SD-WAN Manager, Cisco’s business networking equipment. Attackers can read files on Cisco Catalyst SD-WAN Manager that should be out of reach. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 15 Jun 2026.[1]
Cisco Catalyst SD-WAN Manager is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Cisco has published a fix or advice.
Description
CISA calls it a directory or path traversal in Cisco Catalyst SD-WAN Manager. In its words: “Cisco Catalyst SD-WAN Manager contains a directory or path traversal vulnerability that could allow an authenticated, remote attacker to create a file or overwrite any file on the filesystem of an affected system.”[1]
The CVE record adds: “A vulnerability in the web UI of Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, could allow an authenticated, remote attacker to create a file or overwrite any file on the filesystem of an affected system. This vulnerability exists because the affected software does not properly validate user-supplied input during a file upload process. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected API endpoint of the affected system. A successful exploit could allow the attacker to create or overwrite any file on the underlying operating system. This file could later be used to elevate to root. To exploit this vulnerability, the attacker must have valid credentials with at least a lower-privileged, single-task user account.”[2]
The underlying weakness is path traversal (CWE-22), in MITRE’s list of common software weaknesses.
It scores 6.5 out of 10 on the Common Vulnerability Scoring System, which rates it medium, scored by the organisation that published the CVE using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Cisco’s advisory has them[3]. CISA names the product as Cisco Catalyst SD-WAN Manager.
Most families won’t have Cisco Catalyst SD-WAN Manager; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 15 Jun 2026, within a day of it being made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 29 Jun 2026 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 29%. That’s in the top 2% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Cisco has published a fix or advice.[3] CISA’s required action: “Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes).”[1]
- Check whether you use it.Cisco Catalyst SD-WAN Manager is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 29 Jun 2026 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 6.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 29%.[4] |
See also
Other Cisco Catalyst SD-WAN Manager flaws
- CVE-2026-76504: hex encoding ·
- CVE-2026-20245: improper encoding or escaping of output ·
- CVE-2026-20133: exposure of sensitive information to an unauthorized actor ·
- CVE-2026-20128: storing passwords in a recoverable format ·
Other Cisco flaws
- CVE-2026-76418, Cisco Secure Firewall ASA Software and Cisco Secure FTD Software: unchecked return value to NULL pointer dereference ·
- CVE-2026-76519, Cisco Secure Email Gateway: relative path traversal ·
- CVE-2026-76460, Cisco Identity Services Engine: incorrect use of privileged APIs ·
- CVE-2026-76461, Cisco Secure Email Gateway: SQL injection ·
- CVE-2026-20079, Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management: firewall management center authentication bypass using an alternate path or channel ·
Other path traversal flaws
- CVE-2025-61624, Fortinet products: path traversal ·
- CVE-2021-3199, ONLYOFFICE Docs: server path traversal ·
- CVE-2026-104286, Fortinet FortiMail: path traversal ·
- CVE-2026-93616, Check Point products: path traversal ·
- CVE-2026-66384, JFrog Artifactory: improper limitation of a pathname to a restricted directory ·
Added the same day
- CVE-2026-54420, LiteSpeed cPanel Plugin: UNIX symbolic link (symlink) following ·
Every Cisco flaw on CISA’s list · Everything added in June 2026
References
- ^ Cybersecurity and Infrastructure Security Agency. “Cisco Catalyst SD-WAN Manager Directory or Path Traversal Vulnerability”. Known Exploited Vulnerabilities Catalog, added 15 Jun 2026.
- ^ National Institute of Standards and Technology. “CVE-2026-20262 Detail”. National Vulnerability Database, published 15 Jun 2026.
- ^ Cisco. Advisories and fixes: sec.cloudapps.cisco.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.291, percentile 98.2, 31 Oct 2026.
- CVE Program. “CVE-2026-20262”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.