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CVE-2023-4911 GNU CVE debrief

CVE-2023-4911 affects the GNU C Library and was added to CISA’s Known Exploited Vulnerabilities catalog on 2023-11-21. CISA set a remediation due date of 2023-12-12, so organizations should treat this as an immediate priority and verify whether any affected Linux distributions, appliances, containers, or applications include the vulnerable library version.

Vendor
GNU
Product
GNU C Library
CVSS
HIGH 7.8
CISA KEV
Listed
Original CVE published
2023-11-21
Original CVE updated
2023-11-21
Advisory published
2023-11-21
Advisory updated
2023-11-21

Who should care

Linux platform and infrastructure teams, distribution maintainers, application owners, security operations, incident response, and anyone responsible for systems that depend on the GNU C Library.

Technical summary

CISA identifies CVE-2023-4911 as a known-exploited vulnerability in the GNU C Library. The source item instructs defenders to apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. Because the GNU C Library is a common open-source component used across many products, remediation may need to come from specific downstream vendors rather than a single upstream package alone.

Defensive priority

Immediate

Recommended defensive actions

  • Inventory systems, images, and products that rely on the GNU C Library and identify which vendor or distribution supplies the affected component.
  • Apply vendor-provided mitigations or updates as soon as they are available; if no mitigation exists, follow CISA’s guidance to discontinue use until a fix is available.
  • Check downstream vendor advisories and patch status for any Linux distributions, appliances, or embedded products that bundle the affected library.
  • Validate exposure across servers, containers, and build/runtime images, not just directly managed hosts.
  • Track CISA KEV and vendor notices for remediation updates and verify closure after patching.

Evidence notes

CISA’s KEV feed lists CVE-2023-4911 with dateAdded 2023-11-21 and dueDate 2023-12-12. The source item metadata describes the issue as a GNU C Library buffer overflow vulnerability and states: apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. The supplied source notes also direct readers to official vendor and database references for patching status and confirmation.

Official resources

Publicly disclosed and added to CISA KEV on 2023-11-21.