Ubuntu Fixes libpcap Instruction Validation Flaw
Tech GuruQuick Answer
Ubuntu's libpcap update addresses an instruction-validation flaw that can crash an application processing crafted data. Match the installed library package to your Ubuntu release in USN-8824-1. Include applications and images that carry their own library copy, not just the host package.
Confirm Scope And Apply The Supported Fix
Next step: Find the packet-capture tools and services that use libpcap, install the release-matched Ubuntu update, and restart affected consumers as required. Check ESM access on the older listed releases.
Last verified: 2026-09-25 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.
Scope And Authority
| Product scope | libpcap vulnerability on Ubuntu 26.04 LTS (resolute), Ubuntu 24.04 LTS (noble), Ubuntu 22.04 LTS (jammy), Ubuntu 20.04 ESM (focal), Ubuntu 18.04 ESM (bionic), Ubuntu 16.04 ESM (xenial), Ubuntu 14.04 ESM (trusty) |
|---|---|
| Advisory | USN-8824-1 |
| CVE | CVE-2026-0799 |
| Authoritative release date | 2026-09-25 08:50:02.412924 UTC |
| Authority revision date | 2026-09-25 08:50:02.412924 UTC |
| Affected versions | The Ubuntu releases and source packages enumerated in USN-8824-1: Ubuntu 26.04 LTS (resolute), Ubuntu 24.04 LTS (noble), Ubuntu 22.04 LTS (jammy), Ubuntu 20.04 ESM (focal), Ubuntu 18.04 ESM (bionic), Ubuntu 16.04 ESM (xenial), Ubuntu 14.04 ESM (trusty). |
| Fixed version | bionic: libpcap 1.8.1-6ubuntu1.18.04.2+esm1; focal: libpcap 1.9.1-3ubuntu1.20.04.1+esm1; jammy: libpcap 1.10.1-4ubuntu1.22.04.2; noble: libpcap 1.10.4-4.1ubuntu3.1; resolute: libpcap 1.10.6-1ubuntu1.1; trusty: libpcap 1.5.3-2ubuntu0.1+esm1; xenial: libpcap 1.7.4-2ubuntu0.1+esm1 |
| CVSS base score | Not provided by the authority |
| CVSS severity | Not provided by the authority |
| Exploitation status | Not stated by the authority; no exploitation claim is inferred. |
What Changed
The security boundary is in the library's validation of instructions. A fixed package on disk does not prove an already running process, an embedded build, or a separate container uses the corrected library. Check each deployment's package origin before applying Ubuntu's version numbers to it.
What To Validate Now
- Inventory. Locate libpcap vulnerability on Ubuntu 26.04 LTS (resolute), Ubuntu 24.04 LTS (noble), Ubuntu 22.04 LTS (jammy), Ubuntu 20.04 ESM (focal), Ubuntu 18.04 ESM (bionic), Ubuntu 16.04 ESM (xenial), Ubuntu 14.04 ESM (trusty) deployments, versions, enabled features, exposure paths, owners, and dependent services.
- Establish applicability. Compare each deployment with the authority's affected-version statement: The Ubuntu releases and source packages enumerated in USN-8824-1: Ubuntu 26.04 LTS (resolute), Ubuntu 24.04 LTS (noble), Ubuntu 22.04 LTS (jammy), Ubuntu 20.04 ESM (focal), Ubuntu 18.04 ESM (bionic), Ubuntu 16.04 ESM (xenial), Ubuntu 14.04 ESM (trusty). Do not infer applicability from product family or severity alone.
- Remediate. Apply bionic: libpcap 1.8.1-6ubuntu1.18.04.2+esm1; focal: libpcap 1.9.1-3ubuntu1.20.04.1+esm1; jammy: libpcap 1.10.1-4ubuntu1.22.04.2; noble: libpcap 1.10.4-4.1ubuntu3.1; resolute: libpcap 1.10.6-1ubuntu1.1; trusty: libpcap 1.5.3-2ubuntu0.1+esm1; xenial: libpcap 1.7.4-2ubuntu0.1+esm1 through the supported vendor or project channel, following the current advisory and change-control requirements.
- Validate. Confirm the actual library package and restart status, then test authorized captures and representative filters or offline files. Check error handling with safe regression fixtures; avoid retaining packet contents that disclose credentials or unrelated traffic.
- Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.
Operational Cautions
Use the exact supported release stream and repository. Test dependencies, clusters, integrations, and rollback before broad deployment; a CVSS rating or reachable feature is not evidence of exploitation.
Evidence To Retain
- Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
- UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
- Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.
Related TechGeeks Resources
Authoritative References
Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.
