How severe is CVE-2026-56412?

CVE-2026-56412 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-56412 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-56412?

CVE-2026-56412 affects Libexpat Project Libexpat. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-56412?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-56412 have an EU (EUVD) identifier?

Yes. CVE-2026-56412 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38189.

When was CVE-2026-56412 published?

CVE-2026-56412 was published on 2026-06-21 and last updated on 2026-06-23.

CVE-2026-56412

CVE-2026-56412 is a medium-severity vulnerability in Libexpat Project Libexpat with a CVSS 3.x base score of 4.9. 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-416.

Key facts

Severity: Medium (CVSS 3.x base score 4.9)
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-38189
Weakness: CWE-416
Affected product: Libexpat Project Libexpat
Published: 2026-06-21
Last modified: 2026-06-23

Description

libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219.

Frequently asked questions

What is CVE-2026-56412?: libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219.
How severe is CVE-2026-56412?: CVE-2026-56412 has a CVSS 3.x base score of 4.9, rated medium severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-56412 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-56412?: CVE-2026-56412 affects Libexpat Project Libexpat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-56412?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-56412 have an EU (EUVD) identifier?: Yes. CVE-2026-56412 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38189.
When was CVE-2026-56412 published?: CVE-2026-56412 was published on 2026-06-21 and last updated on 2026-06-23.

References

https://github.com/libexpat/libexpat/pull/1278

Affected products (1)

cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*

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