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TI-2026-40398 Aliases CVE-2026-56003GHSA-3v92-8994-jg8p

libXfont2 computeProps Property Buffer Heap Buffer Overflow

Priority MEDIUM 40CWE-122Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-122 and the CVSS impact.

Summary

A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2 ComputeScaledProperties() before libXfont2 before 2.0.8 could be used by attackers using authenticated X clients to execute code within the X server.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.004 34th percentileScored 2026-11-07
Fix Fixed libXfont2 (X.Org): 2.0.8Red Hat: 11 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
x.orglibXfont2before 2.0.82.0.8Patch availableCNA
  • libXfont2 Vendorx.org Affected before 2.0.8 Fixed in 2.0.8 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:x:libxfont:*:*:*:*:*:*:*:*2.0.0 to before 2.0.8VulnerableX
  • cpe:2.3:a:x:libxfont:*:*:*:*:*:*:*:* Versions 2.0.0 to before 2.0.8 Vulnerable ·X

Remediation

  • Fix · CNA libXfont2 (X.Org) Fixed in 2.0.8

Red Hat 11 advisories

  • RHSA-2026:51059 Released 2026-08-06 · Red Hat rating Important
    libXfont2 security update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) libXfont2-devel-2.0.3-12.el9_6.1
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) libXfont2-2.0.3-12.el9_6.1
  • RHSA-2026:51066 Released 2026-08-06 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) libXfont2-2.0.3-2.el8_6.1
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) libXfont2-2.0.3-2.el8_6.1
  • RHSA-2026:51063 Released 2026-08-06 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) libXfont2-2.0.3-2.el7_9, libXfont2-2.0.3-2.el7_9.ppc
    • Red Hat Enterprise Linux Server Optional (v. 7 ELS) libXfont2-devel-2.0.3-2.el7_9, libXfont2-devel-2.0.3-2.el7_9.ppc
Show 8 more Red Hat advisories
  • RHSA-2026:51067 Released 2026-08-06 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) libXfont2-2.0.3-2.el8_8.1
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) libXfont2-2.0.3-2.el8_8.1
  • RHSA-2026:51058 Released 2026-08-06 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) libXfont2-2.0.3-12.el9_4.1
  • RHSA-2026:51062 Released 2026-08-06 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) libXfont2-2.0.3-12.el9_2.1
  • RHSA-2026:51060 Released 2026-08-06 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) libXfont2-2.0.3-2.el8_4.1
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) libXfont2-2.0.3-2.el8_4.1
  • RHSA-2026:51061 Released 2026-08-06 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) libXfont2-2.0.6-5.el10_0.1
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) libXfont2-devel-2.0.6-5.el10_0.1
  • RHSA-2026:47084 Released 2026-08-03 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux AppStream (v. 9) libXfont2-2.0.3-12.el9_8.1
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libXfont2-devel-2.0.3-12.el9_8.1
  • RHSA-2026:47103 Released 2026-07-28 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux AppStream (v. 8) libXfont2-2.0.3-2.el8_10.1
    • Red Hat Enterprise Linux CRB (v. 8) libXfont2-devel-2.0.3-2.el8_10.1
  • RHSA-2026:47079 Released 2026-07-28 · Red Hat rating Important
    libXfont2 security update
    • Red Hat Enterprise Linux AppStream (v. 10) libXfont2-2.0.6-5.el10_2.1
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libXfont2-devel-2.0.6-5.el10_2.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    X.Org libXfont2 — openwall.com/lists/oss-security/2026/07/08/1

    3 records Highest priority Priority MEDIUM 3 MEDIUM

    Other records, highest priority first

    • TI-2026-40397 libXfont2 PCF Font Parsing Heap Buffer OverflowPriority MEDIUM 40
    • TI-2026-40396 libXfont2 BitmapScaleBitmaps Integer Overflow Heap Buffer OverflowPriority MEDIUM 40
    Show all 3 records → Advisory →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:51059
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:47079
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:47103
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:47084
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:51060
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:51066
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:51067
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:51062
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:51058
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:51061
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:51059
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:51060
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)Fixed RHSA-2026:51066
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:51067
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:47103
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:47079
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:47084
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:51061
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:51063
Red Hat Enterprise Linux Server Optional (v. 7 ELS)Fixed RHSA-2026:51063

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-56003
  2. 2026-10-03 Alias added: GHSA-3v92-8994-jg8p
  3. 2026-10-06 Fix available: RHSA-2026:47084 · Red Hat
  4. 2026-10-06 Fix available: RHSA-2026:47079 · Red Hat
  5. 2026-10-06 Fix available: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) +1 · Red Hat
  6. 2026-10-18 CVSS score changed · Red Hat

References

Patch 2

  • TI-2022-25238 In X.Org X server 20.11 through 21.1.16, when a client application uses easystroke for… CVSS 3.1HIGH 7.7
  • TI-1999-00519 An X server's access control is disabled (e.g. CVSS 2.0HIGH 10.0
  • TI-2021-11657 LookupCol.c in X.Org X through X11R7.7 and libX11 before 1.7.1 might allow remote… CVSS 3.1CRITICAL 9.8
  • TI-2018-10465 An issue was discovered in libX11 through 1.6.5. CVSS 3.0CRITICAL 9.8
  • TI-2004-00826 Multiple vulnerabilities in libXpm for 6.8.1 and earlier, as used in XFree86 and other… CVSS 2.0HIGH 10.0
  • TI-2016-08240 Multiple integer overflows in libXpm before 3.5.12, when a program requests parsing XPM… CVSS 3.0CRITICAL 9.8
See all 206 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences