How severe is CVE-2026-26824?

CVE-2026-26824 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.

Is CVE-2026-26824 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-26824?

CVE-2026-26824 affects Libxls Project Libxls. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-26824?

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

Does CVE-2026-26824 have an EU (EUVD) identifier?

Yes. CVE-2026-26824 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34178.

When was CVE-2026-26824 published?

CVE-2026-26824 was published on 2026-06-03 and last updated on 2026-06-17.

CVE-2026-26824

CVE-2026-26824 is a medium-severity vulnerability in Libxls Project Libxls with a CVSS 3.x base score of 6.5. 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-457.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-34178
Weakness: CWE-457
Affected product: Libxls Project Libxls
Published: 2026-06-03
Last modified: 2026-06-17

Description

libxls through version 1.6.3 contains a use of uninitialized memory vulnerability in the OLE container parser. Memory allocated for the Master Sector Allocation Table (MSAT) in read_MSAT() is not fully initialized before being consumed by ole2_validate_sector_chain(), which may result in application crashes or potential information disclosure when processing a crafted XLS file

Frequently asked questions

What is CVE-2026-26824?: libxls through version 1.6.3 contains a use of uninitialized memory vulnerability in the OLE container parser. Memory allocated for the Master Sector Allocation Table (MSAT) in read_MSAT() is not fully initialized before being consumed by ole2_validate_sector_chain(), which may result in application crashes or potential information disclosure when processing a crafted XLS file
How severe is CVE-2026-26824?: CVE-2026-26824 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.
Is CVE-2026-26824 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-26824?: CVE-2026-26824 affects Libxls Project Libxls. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-26824?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-26824 have an EU (EUVD) identifier?: Yes. CVE-2026-26824 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34178.
When was CVE-2026-26824 published?: CVE-2026-26824 was published on 2026-06-03 and last updated on 2026-06-17.

References

https://github.com/libxls/libxls/issues/155

Affected products (1)

cpe:2.3:a:libxls_project:libxls:*:*:*:*:*:*:*:*

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