How severe is CVE-2026-5443?

CVE-2026-5443 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-5443 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-5443?

CVE-2026-5443 affects Orthanc-server Orthanc. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-5443?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-5443 have an EU (EUVD) identifier?

Yes. CVE-2026-5443 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20922.

When was CVE-2026-5443 published?

CVE-2026-5443 was published on 2026-04-09 and last updated on 2026-06-17.

CVE-2026-5443

CVE-2026-5443 is a critical-severity vulnerability in Orthanc-server Orthanc with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-20922
Weakness: CWE-787
Affected product: Orthanc-server Orthanc
Published: 2026-04-09
Last modified: 2026-06-17

Description

A heap buffer overflow vulnerability exists during the decoding of `PALETTE COLOR` DICOM images. Pixel length validation uses 32-bit multiplication for width and height calculations. If these values overflow, the validation check incorrectly succeeds, allowing the decoder to read and write to memory beyond allocated buffers.

Frequently asked questions

What is CVE-2026-5443?: A heap buffer overflow vulnerability exists during the decoding of `PALETTE COLOR` DICOM images. Pixel length validation uses 32-bit multiplication for width and height calculations. If these values overflow, the validation check incorrectly succeeds, allowing the decoder to read and write to memory beyond allocated buffers.
How severe is CVE-2026-5443?: CVE-2026-5443 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-5443 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-5443?: CVE-2026-5443 affects Orthanc-server Orthanc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-5443?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-5443 have an EU (EUVD) identifier?: Yes. CVE-2026-5443 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20922.
When was CVE-2026-5443 published?: CVE-2026-5443 was published on 2026-04-09 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:orthanc-server:orthanc:*:*:*:*:*:*:*:*

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