Quick answers
- Is CVE-2026-18341 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-18341 being exploited in the wild.
- How severe is CVE-2026-18341?
- Medium severity, with a CVSS score of 6.3, published 4 September 2026.
- Which products and versions are affected?
- IBM I 7.3 7.3; IBM I 7.4 7.4; IBM I 7.5 7.5; IBM I 7.6 7.6.
- Is there a fix for CVE-2026-18341?
- A patch was published on 2026-09-04: PTFs released: MJ11326 (7.6), MJ11327 (7.5), MJ11328 (7.4), MJ11329 (7.3) Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-18341 attacked?
- It is attacked over the network, in an operating system.
- Am I affected by CVE-2026-18341?
- Check whether you run IBM I 7.3, IBM I 7.4, IBM I 7.5 or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a heap-based buffer overflow caused by an integer underflow (CWE-122). A remote authenticated attacker can send a specially crafted request to the affected system, triggering the integer underflow condition and corrupting memory. The attack vector is network-based, requires prior authentication (PR:L), and does not require user interaction. Successful exploitation can result in partial loss of confidentiality, integrity, and availability. IBM has released patches (PTFs) for all affected versions: MJ11326 (7.6), MJ11327 (7.5), MJ11328 (7.4), and MJ11329 (7.3).
Affected products
- IBM i 7.6 7.6
- IBM i 7.5 7.5
- IBM i 7.4 7.4
- IBM i 7.3 7.3
Timeline
- 2026-09-04: disclosed
- 2026-09-04: patched: PTFs released: MJ11326 (7.6), MJ11327 (7.5), MJ11328 (7.4), MJ11329 (7.3)