How severe is CVE-2026-20263?

CVE-2026-20263 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-20263 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-20263?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-20263 published?

CVE-2026-20263 was published on 2026-08-05 and last updated on 2026-08-06.

CVE-2026-20263

CVE-2026-20263 is a high-severity vulnerability with a CVSS 3.x base score of 8.6. 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-388.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 0% (26th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-388
Published: 2026-08-05
Last modified: 2026-08-06

Description

A vulnerability in the Blocks Extensible Exchange Protocol (BEEP) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling when parsing a specific BEEP SOAP request. An attacker could exploit this vulnerability by sending a specific BEEP SOAP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.

Frequently asked questions

What is CVE-2026-20263?: A vulnerability in the Blocks Extensible Exchange Protocol (BEEP) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling when parsing a specific BEEP SOAP request. An attacker could exploit this vulnerability by sending a specific BEEP SOAP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.
How severe is CVE-2026-20263?: CVE-2026-20263 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-20263 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-20263?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-20263 published?: CVE-2026-20263 was published on 2026-08-05 and last updated on 2026-08-06.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-bing-MGHrFAkd

Other CWE-388 vulnerabilities

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CVE-2017-5401 — Critical (CVSS 9.8): A crash triggerable by web content in which an "ErrorResult" references unassigned memory due to a logic error. The…
CVE-2016-10466 — Critical (CVSS 9.8): In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Mobile and Snapdragon Wear MDM9206,…
CVE-2016-10414 — Critical (CVSS 9.8): In Android before 2018-04-05 or earlier security patch level on Qualcomm Small Cell SoC, Snapdragon Automobile,…
CVE-2015-9120 — Critical (CVSS 9.8): In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Automobile, Snapdragon Mobile, and…
CVE-2014-9985 — Critical (CVSS 9.8): In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Mobile MDM9635M, SD 400, and SD…

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