Remote crash via undersized signed PubSub message
Published Jul 30, 2026 · Updated Jul 30, 2026
Integer underflow in open62541 allows remote attackers to crash PubSub consumers by sending a crafted signed UDP packet. In verifyAndDecrypt in src/pubsub/ua_pubsub_security.c, subtracting the expected signature size from a shorter message length wraps size_t, causing mbedTLS to read unmapped memory. The affected path requires a PubSub consumer configured for signature validation; the published impact is a process crash without reported data disclosure or modification.
Summary
What happened
Integer underflow in open62541 allows remote attackers to crash PubSub consumers by sending a crafted signed UDP packet. In verifyAndDecrypt in src/pubsub/ua_pubsub_security.c, subtracting the expected signature size from a shorter message length wraps size_t, causing mbedTLS to read unmapped memory. The affected path requires a PubSub consumer configured for signature validation; the published impact is a process crash without reported data disclosure or modification.
The record
- CVE
- CVE-2026-63362
- Published
- Jul 30, 2026
- Updated
- Jul 30, 2026
- Vendor
- o6 Automation GmbH
- Product
- open62541
- Classifications
- CWE-191, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 30, 2026CVE publishedPublication date reported by the CVE source.
- Jul 30, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.3.0 <=1.3.17
- Affected versionversion=1.4.0 <=1.4.16
- Affected versionversion=1.5.0 <=1.5.4
- Affected versionversion=master
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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