Traffic interruption via corrupted EPNI interrupt handling
Published Mar 11, 2026 · Updated Mar 11, 2026
Denial of service in Cisco IOS XR Software allows remote attackers to interrupt interface traffic with a continuous crafted-packet flow. During heavy transit traffic, an EPNI Aligner interrupt corrupts packets and causes the NPU and ASIC to stop processing them. Exposure is limited to listed NCS 5700 hardware and third-party systems with a Jericho 2 ASIC; successful exploitation produces persistent heavy packet loss.
Summary
What happened
Denial of service in Cisco IOS XR Software allows remote attackers to interrupt interface traffic with a continuous crafted-packet flow. During heavy transit traffic, an EPNI Aligner interrupt corrupts packets and causes the NPU and ASIC to stop processing them. Exposure is limited to listed NCS 5700 hardware and third-party systems with a Jericho 2 ASIC; successful exploitation produces persistent heavy packet loss.
The record
- CVE
- CVE-2026-20118
- Published
- Mar 11, 2026
- Updated
- Mar 11, 2026
- Vendor
- ClamAV
- Product
- Cisco IOS XR Software
- Classifications
- CWE-460, T1498
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 11, 2026CVE publishedPublication date reported by the CVE source.
- Mar 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=24.1.1
- Affected versionversion=24.1.2
- Affected versionversion=24.2.1
- Affected versionversion=24.2.11
- Affected versionversion=24.2.2
- Affected versionversion=24.2.20
- Affected versionversion=24.2.21
- Affected versionversion=24.3.1
- Affected versionversion=24.3.2
- Affected versionversion=24.3.20
- Affected versionversion=24.3.30
- Affected versionversion=24.4.1
- Affected versionversion=24.4.2
- Affected versionversion=24.4.30
- Affected versionversion=25.1.1
- Affected versionversion=25.1.2
- Affected versionversion=7.10.1
- Affected versionversion=7.10.2
- Affected versionversion=7.11.1
- Affected versionversion=7.11.2
- Affected versionversion=7.11.21
- Affected versionversion=7.9.1
- Affected versionversion=7.9.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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