CVE-2026-63559 PUBLISHED

An integer overflow in the UA_Variant arrayDimensions product computation in open62541 may allow a remote attacker to read out-of-bounds heap memory, potentially disclosing sensitive information.

o6 Automation has prepared mitigations and fixes to address these issues and recommends that users update to the newest version. The new version can be obtained by contacting o6 Automation   https://www.o6-automation.com/contact or by downloading from the following locations: 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

For more information, see open62541 Security Advisories SA-2026-0012, SA-2026-0014, and SA-2026-0015 or contact o6 Automation:  https://www.o6-automation.com/contact

• Asher Davila of Palo Alto Networks reported this vulnerability to CISA. finder

• 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

• CWE-190 CWE