Vulnerability · Published Jul 30, 2026 · Assigned by icscert
CVE-2026-63362o6 Automation open62541 Integer Underflow
Medium 5.9
In plain English
A medium-severity security flaw in open62541 from o6 Automation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.8% (higher than 79% of all known vulnerabilities).
Severity (CVSS 3.1)5.9Medium
Exploit odds (30 days)1.8%top 21.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
An unsigned integer underflow in the PubSub signature verification path in open62541 may allow a remote attacker to cause a denial of service via a crafted UDP packet.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | open62541 | no fix listed | DEBIAN-CVE-2026-63362 |
| Debian:14 | open62541 | no fix listed | DEBIAN-CVE-2026-63362 |
| Ubuntu:26.04:LTS | open62541 | no fix listed | UBUNTU-CVE-2026-63362 |
| Ubuntu:26.10 | open62541 | no fix listed | UBUNTU-CVE-2026-63362 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| o6 Automation | open62541 | 1.3.0 – through 1.3.171.4.0 – through 1.4.161.5.0 – through 1.5.4master |
Weakness: CWE-191 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://www.o6-automation.com/contact
- https://github.com/open62541/open62541/pull/8235/commits/b666d35769ce63998442e4d0810a3fb10b50179f
- https://github.com/open62541/open62541/pull/8236/commits/06b99fef667c8ec5bdf0605b4f00c84fcc1d3a60
- https://github.com/open62541/open62541/pull/8237/commits/1b71d9c5d9c4d02d4729b8903a52e9f530bf804e
- https://github.com/open62541/open62541/pull/8238/commits/afab4107bfd161da9ce8bb30ed77f3968c9c97df
- https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-08
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-08.json