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CVE Record

CVE-2026-50264: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: out-of-bounds heap write in dri2 drigetbuffers/drigetbufferswithformat

An out-of-bounds write flaw was found in the X.Org X server and Xwayland in DRIGetBuffers/DRIGetBuffersWithFormat. A client that requests multiple DRI2BufferBackLeft attachments and one DRI2BufferFrontLeft can trigger an out-of-bounds heap write. This may be used to crash the server, or for privilege escalation if the X server runs as root.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-50264 is a high-severity memory corruption flaw in X.Org X server and Xwayland. A local authenticated client can crash the graphical server and, when X runs as root, may escalate privileges. This matters most on Linux desktops, VDI, jump hosts, and servers with GUI or remote desktop components.

Executive priority

Treat as a prompt patching priority for GUI-capable Linux systems, especially multi-user or remote-access environments. It is not evidenced as actively exploited, but the privilege-escalation impact is material once an attacker has local access.

Technical view

The flaw is a CWE-787 out-of-bounds heap write in DRI2 DRIGetBuffers and DRIGetBuffersWithFormat handling. A client requesting multiple DRI2BufferBackLeft attachments plus one DRI2BufferFrontLeft can corrupt heap memory. The listed CVSS is 7.8: local attack vector, low complexity, low privileges, no user interaction, high CIA impact.

Likely exposure

Exposure is likely where affected Red Hat Enterprise Linux 7 ELS, 8, 9, 10, EUS, AUS, TUS, SAP, or related streams run xorg-x11-server, xorg-x11-server-Xwayland, or tigervnc packages.

Exploitation context

The bundle does not show CISA KEV listing or active exploitation. Exploitation requires a local client context, so internet-wide remote scanning is not the primary risk. The practical concern is privilege escalation after local access or compromise of a GUI session.

Researcher notes

Focus validation on package presence, graphical session exposure, and whether X runs with elevated privileges. The public bundle describes the trigger class but does not provide exploit maturity, exploit availability, or vendor-independent mitigation detail beyond Red Hat advisories.

Mitigation direction

  • Apply the relevant Red Hat RHSA updates for affected packages.
  • Prioritize desktops, VDI, jump hosts, and remote GUI servers.
  • Inventory xorg-x11-server, Xwayland, and tigervnc package versions.
  • Remove or disable unnecessary GUI and remote desktop components.
  • For non-Red Hat builds, check the vendor’s X.Org or Xwayland guidance.

Validation and detection

  • Confirm whether affected packages are installed on each Linux asset.
  • Compare installed package versions against the Red Hat affected-version list.
  • Check whether systems run Xorg, Xwayland, TigerVNC, or GUI sessions.
  • Verify applicable RHSA advisories are installed through patch management.
  • Track exceptions for systems that cannot be updated promptly.
Prepared
Confidence
high
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-787: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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description · low confidence lookup

Privilege behavior lookup

The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2026-50264 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
7Timeline events
2ADP providers
27Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9redhat
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2026-50264Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. ADP timelineredhat-SADP

    Reported to Red Hat.

  2. Source timelineredhat

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. Source timelineredhat

    Made public.

  5. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  6. CVE publishedCVE Program

    The CVE record was published.

  7. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPxorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds heap write in DRI2 DRIGetBuffers/DRIGetBuffersWithFormat
other:Red Hat severity ratingcvssV3_1
  • 2026-05-15T03:14:46.000Z: Reported to Red Hat.
  • 2026-06-02T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Red HatRed Hat Enterprise Linux 10xorg-x11-server-Xwayland, 0:24.1.9-4.el10_2.2affected
Red HatRed Hat Enterprise Linux 10.0 Extended Update Supportxorg-x11-server-Xwayland, 0:24.1.5-6.el10_0.1affected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Supportxorg-x11-server, 0:1.20.4-35.el7_9affected
Red HatRed Hat Enterprise Linux 8xorg-x11-server-Xwayland, 0:21.1.3-20.el8_10.2affected
Red HatRed Hat Enterprise Linux 8xorg-x11-server, 0:1.20.11-28.el8_10.2affected
Red HatRed Hat Enterprise Linux 8tigervnc, 0:1.15.0-10.el8_10affected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Supportxorg-x11-server, 0:1.20.10-5.el8_4affected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-Onxorg-x11-server, 0:1.20.10-5.el8_4affected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Supportxorg-x11-server, 0:1.20.11-8.el8_6affected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Supportxorg-x11-server-Xwayland, 0:21.1.3-2.el8_6.7affected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-Onxorg-x11-server, 0:1.20.11-8.el8_6affected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-Onxorg-x11-server-Xwayland, 0:21.1.3-2.el8_6.7affected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Servicexorg-x11-server, 0:1.20.11-19.el8_8affected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Servicexorg-x11-server-Xwayland, 0:21.1.3-13.el8_8.1affected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutionsxorg-x11-server, 0:1.20.11-19.el8_8affected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutionsxorg-x11-server-Xwayland, 0:21.1.3-13.el8_8.1affected
Red HatRed Hat Enterprise Linux 9xorg-x11-server-Xwayland, 0:24.1.9-4.el9_8.2affected
Red HatRed Hat Enterprise Linux 9xorg-x11-server, 0:1.20.11-34.el9_8.2affected
Red HatRed Hat Enterprise Linux 9tigervnc, 0:1.15.0-7.el9_8.2affected
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP Solutionsxorg-x11-server, 0:1.20.11-21.el9_2affected
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP Solutionsxorg-x11-server-Xwayland, 0:21.1.3-10.el9_2.1affected
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP Solutionsxorg-x11-server, 0:1.20.11-29.el9_4affected
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP Solutionsxorg-x11-server-Xwayland, 0:22.1.9-8.el9_4.1affected
Red HatRed Hat Enterprise Linux 9.6 Extended Update Supportxorg-x11-server, 0:1.20.11-34.el9_6affected
Red HatRed Hat Enterprise Linux 9.6 Extended Update Supportxorg-x11-server-Xwayland, 0:23.2.7-6.el9_6.1affected
Red HatRed Hat Enterprise Linux 6tigervncaffected
Red HatRed Hat Enterprise Linux 6xorg-x11-serverunknown
Red HatRed Hat Enterprise Linux 7tigervncaffected
Weakness

CWE details

CWE-787

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-787 · source CWE mapping

Out-of-bounds Write

Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs