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Full vulnerability report · 2026
CVE-2026-56001High confidence

libXfont2 BitmapScaleBitmaps Integer Overflow Heap Buffer Overflow

X.Org · libXfont2

8.5HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:High, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.62% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs X.Org libXfont2 and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

5 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcelibxfontVendor fix publishedDebian records a fixed source-package version for this release.1:2.0.6-1+deb13u1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcelibxfontVendor fix publishedDebian records a fixed source-package version for this release.1:2.0.6-1+deb12u1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcelibxfontVendor fix publishedDebian records a fixed source-package version for this release.1:2.0.8-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcelibxfontVendor fix publishedDebian records a fixed source-package version for this release.1:2.0.8-1Debian Security Tracker ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelibxfontVendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.1:2.0.6-1+deb13u1build0.24.04.2Canonical Ubuntu Security ↗Source updated 5 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-56001 · CSAF 2.0 · revision 12 · interimSUSE Product Security TeamCVE-2026-56001
59 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • libXfont2 as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • libXfont2-2 as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • libXfont2 as component of SUSE Linux Enterprise High Performance Computing 15 SP1
  • libXfont2-2 as component of SUSE Linux Enterprise High Performance Computing 15 SP1
  • libXfont2-devel as component of SUSE Linux Enterprise High Performance Computing 15 SP1
  • libXfont2 as component of SUSE Linux Enterprise High Performance Computing 15 SP2
  • libXfont2-2 as component of SUSE Linux Enterprise High Performance Computing 15 SP2
  • libXfont2-devel as component of SUSE Linux Enterprise High Performance Computing 15 SP2
  • libXfont2 as component of SUSE Linux Enterprise High Performance Computing 15 SP3
  • libXfont2-2 as component of SUSE Linux Enterprise High Performance Computing 15 SP3
  • libXfont2-devel as component of SUSE Linux Enterprise High Performance Computing 15 SP3
  • libXfont2 as component of SUSE Linux Enterprise Server 12 SP4-LTSS
Summary
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
Remediation
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-42210

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

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

What

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

Why

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

What

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

Why

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Heap-based Buffer Overflow → execute code or commands in the affected security context
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-122 ↗

CWE-122: Heap-based Buffer Overflow. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkRemote code executionCWE-122
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-2378X.Org X11 Server (libXfont2): Mehrere Schwachstellen ermöglichen Ausführen von beliebigem Programmcode mit Administratorrechten

Ein lokaler Angreifer kann mehrere Schwachstellen in X.Org X11 ausnutzen, um erweiterte Berechtigungen zu erlangen und beliebigen Code mit Root-Rechten auszuführen.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0873Multiples vulnérabilités dans Microsoft Azure Linux

tin de sécurité Microsoft Azure Linux CVE-2026-8926 du 04 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-8927 du 04 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-8932 du 04 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-9079 du 04 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-12480 du 07 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-54886 du 07 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-54908 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-56000 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-56001 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-56002 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-56003 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-59995 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-59996 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-59997 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-59999 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-60000 du 09 juillet 2026 Bulletin de sécurité Microsoft Azure Linux CVE-2026-60001 du 09 juillet 2026 Bulletin de sé

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-023201X.OrgのLibXFontにおけるヒープベースのバッファオーバーフローの脆弱性

libXfont2のバージョン2.0.8以前のBitmapScaleBitmapsにおけるヒープバッファオーバーフローは、32ビットサイズのオーバーフローが原因であり、Xサーバーにアクセス可能な攻撃者がXサーバー内でコードを実行するために悪用する可能性があります。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 8 Jul 2026 · Last source change 9 Jul 2026, 03:55 UTC · CWE-122 · Heap-based Buffer Overflow

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-42210
Product sourceVendor CSAF · SUSE Product Security Team
Remediation sourceVendor CSAF · SUSE Product Security Team
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-42210↗Vendor CSAF · SUSE Product Security Team↗CVE authority or vendor reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-56001 · cve.blacktree.nl