Affects core GNU C Library (glibc) widely used across OSs; disruption potential across IT environments.
CVE-2026-5358
Buffer overflow in glibc nis_local_principal can spoof UDP responses.
Is CVE-2026-5358 being exploited?
Not confirmed. CVE-2026-5358 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-5358?
CVE-2026-5358 is rated Critical with a CVSS score of 9.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-5358?
Yes. A fix has been recorded for CVE-2026-5358. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-5358 affect?
CVE-2026-5358 affects GNU C Library (glibc) <= 2.43. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-5358?
Upgrade glibc to >= 2.44 and remove NIS usage.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Spoofed UDP replies can overflow the buffer and overwrite adjacent data, risking data corruption and potential code execution.
Immediate action required