CVE-2026-4942
MEDIUM 5.9IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to send a specifically crafted message and downgrade the Transport Layer Security (TLS) protocol to a version disabled in the server configuration.
NO EXPLOITATION SIGNALS
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 33rd percentile
○ In CISA KEV
○ Public exploit / PoC
Impact if exploited
5.9CVSS 3.1 · MEDIUM
- ConfidentialityHigh
- IntegrityNone
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ⚠Complexity: Needs a race window or specific setup
✓ 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-2026-4942/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-2026-4942/poc.json
Weakness (CWE)
- CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
All CVSS metrics
- MEDIUM 5.9 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - MEDIUM 5.9 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N