CVE-2026-17255
MEDIUM 4.3IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to cause a denial of service due to improper validation of the prefix length in ICMPv6 Router Advertisements.
NO EXPLOITATION SIGNALS
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
—EPSS not yet scored
○ In CISA KEV
○ Public exploit / PoC
Impact if exploited
4.3CVSS 3.1 · MEDIUM
- ConfidentialityNone
- IntegrityNone
- AvailabilityLow
What an attacker needs
- ⚠Access: Must sit on the same / adjacent network
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-17255/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-17255/poc.json
Weakness (CWE)
- CWE-787: Out-of-bounds Write
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
All CVSS metrics
- MEDIUM 4.3 v3.1 · CNA Primary
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - MEDIUM 4.3 v3.1 · NVD Primary
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L