CVE-2025-20248
mediumpriority · track · 0EPSS 0.001 · 1 %ileDEEUNLRUUSEPSS · scored 2026-10-27
A vulnerability in the installation process of Cisco IOS XR Software could allow an authenticated, local attacker to bypass Cisco IOS XR Software image signature verification and load unsigned software on an affected device. To exploit this vulnerability, the attacker must have root-system privileges on the affected device. This vulnerability is due to incomplete validation of files during the installation of an .iso file. An attacker could exploit this vulnerability by modifying contents of the .iso image and then installing and activating it on the device. A successful exploit could allow the attacker to load an unsigned file as part of the image activation process.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedCisco IOS XR Softwarecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (191)
Products and version ranges known to be affected.
advisories (3)
Vendor and ecosystem advisories describing this.
- NCSC-2025-0286Kwetsbaarheden verholpen in Cisco IOS XR SoftwareNL2025-09-11csaf · ncsc_nlNL
Cisco heeft kwetsbaarheden verholpen in Cisco IOS XR Software.
- WID-SEC-W-2025-2032Cisco IOS XR: Mehrere SchwachstellenDeutsch2025-09-10csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Cisco IOS XR ausnutzen, um Sicherheitsvorkehrungen zu umgehen und um einen Denial-of-Service-Zustand zu verursachen.
- cisco-sa-xrsig-UY4zRUCGCisco IOS XR Software Image Verification Bypass Vulnerability2025-09-10csaf · cisco_csafUS
A vulnerability in the installation process of Cisco IOS XR Software could allow an authenticated, local attacker to bypass Cisco IOS XR Software image signature verification and load unsigned software on an affected device. To exploit this vulnerability, the attacker must have root-system privileges on the affected device. This vulnerability is due to incomplete validation of files during the installation of an .iso file. An attacker could exploit this vulnerability by modifying contents of the .iso image and then installing and activating it on the device. A successful exploit could allow the attacker to load an unsigned file as part of the image activation process. Note: Because exploitation of this vulnerability could result in the attacker bypassing Cisco image verification, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the September 2025 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2025 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75549"].
also known as (5)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (4)
External citations — patches, advisories, analysis.
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xrsig-UY4zRUCGcnnvd
- https://vigilance.fr/vulnerability/Cisco-IOS-XR-code-execution-via-Image-Verification-Bypass-48203cnnvd
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xrsig-UY4zRUCGenisa_euvd
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xrsig-UY4zRUCGnvd
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