Open1722: Numeric Truncation Error
CVE-2026-73523 is a high-severity numeric truncation error vulnerability in Open1722 from Covesa, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Open1722 versions: 0.9.2 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.55% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Open1722 you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 7.5 | High | CNA (vulncheck.com) |
Official description
COVESA Open1722 through 0.9.2 contains an integer truncation vulnerability in acf-can-listener.c that allows unauthenticated remote attackers to cause the CAN listener to transmit process stack memory onto the CAN bus by sending a rejected UDP datagram with a matching AVTP stream ID. The num_can_msgs variable declared as uint8_t truncates the -1 error return value from avtp_to_can() to 255, causing a write loop to iterate 255 times over a 15-slot stack array and leak approximately 18 KB of adjacent stack memory as roughly 240 CAN frames to any recipient on the CAN bus.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Numeric Truncation Error
Truncation errors occur when a primitive is cast to a primitive of a smaller size and data is lost in the conversion.
How developers prevent this class of flaw
- Ensure that no casts, implicit or explicit, take place that move from a larger size primitive or a smaller size primitive.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Open1722
- 7.5 High severity
Recent Numeric Truncation Error vulnerabilities
- 7.5 High severity
- 7.7 High severity
- 8.8 High severity
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