How severe is CVE-2026-56001?

CVE-2026-56001 has a CVSS 3.x base score of 8.5, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-56001 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-56001?

CVE-2026-56001 affects X Libxfont. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-56001?

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

When was CVE-2026-56001 published?

CVE-2026-56001 was published on 2026-07-08 and last updated on 2026-07-09.

CVE-2026-56001

CVE-2026-56001 is a high-severity vulnerability in X Libxfont with a CVSS 3.x base score of 8.5. 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-122.

Key facts

Severity: High (CVSS 3.x base score 8.5)
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-122
Affected product: X Libxfont
Published: 2026-07-08
Last modified: 2026-07-09

Description

A heap buffer overflow in BitmapScaleBitmaps in libXfont2 before 2.0.8 due to an overflowing 32bit size could be used by attackers able to access the X Server to execute code within the X server cont

Frequently asked questions

What is CVE-2026-56001?: A heap buffer overflow in BitmapScaleBitmaps in libXfont2 before 2.0.8 due to an overflowing 32bit size could be used by attackers able to access the X Server to execute code within the X server cont
How severe is CVE-2026-56001?: CVE-2026-56001 has a CVSS 3.x base score of 8.5, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-56001 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-56001?: CVE-2026-56001 affects X Libxfont. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-56001?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-56001 published?: CVE-2026-56001 was published on 2026-07-08 and last updated on 2026-07-09.

References

Affected products (1)

cpe:2.3:a:x:libxfont:*:*:*:*:*:*:*:*

More vulnerabilities in X Libxfont

CVE-2007-5199 — Critical (CVSS 9.8): A single byte overflow in catalogue.c in X.Org libXfont 1.3.1 allows remote attackers to have unspecified impact.
CVE-2013-6462 — Critical (CVSS 9.3): Stack-based buffer overflow in the bdfReadCharacters function in bitmap/bdfread.c in X.Org libXfont 1.1 through 1.4.6…
CVE-2011-2895 — Critical (CVSS 9.3): The LZW decompressor in (1) the BufCompressedFill function in fontfile/decompress.c in X.Org libXfont before 1.4.4 and…
CVE-2026-56003 — High (CVSS 8.5): A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2…
CVE-2026-56002 — High (CVSS 8.5): A heap bufferflow in pcfReadFont() due to missing glyph bounds checking in libXfont2 before 2.0.8 allows attackers…
CVE-2015-1804 — High (CVSS 8.5): The bdfReadCharacters function in bitmap/bdfread.c in X.Org libXfont before 1.4.9 and 1.5.x before 1.5.1 does not…

All CVEs affecting X Libxfont →

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