Is CVE-2026-41503 in the CISA KEV catalog?

No. CVE-2026-41503 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-41503?

CVE-2026-41503 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2026-41503?

CVE-2026-41503 has an EPSS score of 0.41% (33th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-41503

HIGH

7.5

CVSS v3

NVD

Description

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, an out-of-bounds read vulnerability in bacnet-stack's ReadPropertyMultiple service property decoder allows unauthenticated remote attackers to read past allocated buffer boundaries by sending an RPM request with a truncated property list. The vulnerability stems from rpm_decode_object_property() calling the deprecated decode_tag_number_and_value() function at src/bacnet/rpm.c:344, which accepts no buffer length parameter and reads blindly from whatever pointer it receives. A crafted BACnet/IP packet with a 1-byte property payload containing an extended tag marker (0xF9) causes the decoder to read 1 byte past the end of the buffer, leading to crashes on embedded BACnet devices. The vulnerability exists in src/bacnet/rpm.c and affects any deployment that enables the ReadPropertyMultiple confirmed service handler (enabled by default in the reference server). This vulnerability is fixed in 1.4.3.

CWE-125Out-of-bounds Read

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.41%probability of exploitation in 30 days

33rdpercentile

Low risk: more likely to be exploited than 33% of all known CVEs.

References

https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-5w2v-mwqj-pr2c

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-28.