Adjacent compromise through incorrect calculations
Published Sep 2, 2026 · Updated Sep 3, 2026
Incorrect calculations in all Cisco IOS XR Software releases allow attackers to compromise confidentiality, integrity, and availability. The umbrella record covers incorrect buffer-size calculation, integer overflow or wraparound, and integer underflow, but Cisco does not disclose the affected functions, inputs, or resulting operations. The highest-impact underlying flaw requires adjacent network access but no privileges or user interaction, and Cisco reports no known malicious use.
Summary
What happened
Incorrect calculations in all Cisco IOS XR Software releases allow attackers to compromise confidentiality, integrity, and availability. The umbrella record covers incorrect buffer-size calculation, integer overflow or wraparound, and integer underflow, but Cisco does not disclose the affected functions, inputs, or resulting operations. The highest-impact underlying flaw requires adjacent network access but no privileges or user interaction, and Cisco reports no known malicious use.
The record
- CVE
- CVE-2026-20275
- Published
- Sep 2, 2026
- Updated
- Sep 3, 2026
- Vendor
- ClamAV
- Product
- Cisco IOS XR Software
- Classifications
- CWE-682
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 2, 2026CVE publishedPublication date reported by the CVE source.
- Sep 3, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
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=24.4.10
- Affected versionversion=24.4.15
- Affected versionversion=24.4.2
- Affected versionversion=24.4.30
- Affected versionversion=25.1.1
- Affected versionversion=25.1.2
- Affected versionversion=25.1.30
- Affected versionversion=25.2.1
- Affected versionversion=25.2.15
- Affected versionversion=25.2.2
- Affected versionversion=25.2.30
- Affected versionversion=25.3.1
- Affected versionversion=25.3.15
- Affected versionversion=25.4.1
- Affected versionversion=25.4.2
- Affected versionversion=25.4.201
- Affected versionversion=25.4.30
- Affected versionversion=26.1.1
- Affected versionversion=26.1.2
- Affected versionversion=26.2.1
- Affected versionversion=26.2.100
- Affected versionversion=26.2.101
- Affected versionversion=6.5.25
- Affected versionversion=6.5.26
- Affected versionversion=6.5.28
- Affected versionversion=6.5.29
- Affected versionversion=6.5.31
- Affected versionversion=6.5.32
- Affected versionversion=6.5.33
- Affected versionversion=6.5.35
- Affected versionversion=6.5.351
- Affected versionversion=6.5.352
- Affected versionversion=6.5.353
- Affected versionversion=6.5.90
- Affected versionversion=6.7.1
- Affected versionversion=6.7.2
- Affected versionversion=6.7.3
- Affected versionversion=6.7.35
- Affected versionversion=6.7.4
- Affected versionversion=6.8.1
- Affected versionversion=6.8.2
- Affected versionversion=6.9.1
- Affected versionversion=6.9.2
- Affected versionversion=7.0.0
- Affected versionversion=7.0.1
- Affected versionversion=7.0.11
- Affected versionversion=7.0.12
- Affected versionversion=7.0.14
- Affected versionversion=7.0.2
- Affected versionversion=7.0.90
- Affected versionversion=7.10.1
- Affected versionversion=7.10.2
- Affected versionversion=7.1.1
- Affected versionversion=7.11.1
- Affected versionversion=7.11.2
- Affected versionversion=7.11.21
- Affected versionversion=7.1.15
- Affected versionversion=7.1.2
- Affected versionversion=7.1.25
- Affected versionversion=7.1.3
- Affected versionversion=7.2.0
- Affected versionversion=7.2.1
- Affected versionversion=7.2.12
- Affected versionversion=7.2.2
- Affected versionversion=7.3.1
- Affected versionversion=7.3.15
- Affected versionversion=7.3.16
- Affected versionversion=7.3.2
- Affected versionversion=7.3.27
- Affected versionversion=7.3.3
- Affected versionversion=7.3.4
- Affected versionversion=7.3.5
- Affected versionversion=7.3.6
- Affected versionversion=7.4.1
- Affected versionversion=7.4.15
- Affected versionversion=7.4.16
- Affected versionversion=7.4.2
- Affected versionversion=7.5.1
- Affected versionversion=7.5.12
- Affected versionversion=7.5.2
- Affected versionversion=7.5.3
- Affected versionversion=7.5.4
- Affected versionversion=7.5.5
- Affected versionversion=7.5.52
- Affected versionversion=7.6.1
- Affected versionversion=7.6.15
- Affected versionversion=7.6.2
- Affected versionversion=7.6.3
- Affected versionversion=7.7.1
- Affected versionversion=7.7.2
- Affected versionversion=7.7.21
- Affected versionversion=7.8.1
- Affected versionversion=7.8.12
- Affected versionversion=7.8.2
- Affected versionversion=7.8.22
- Affected versionversion=7.8.23
- Affected versionversion=7.9.1
- Affected versionversion=7.9.2
- Affected versionversion=7.9.21
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.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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