LiveActive security incident?Get immediate response
CVE Record

CVE-2025-49176: Xorg-x11-server-xwayland: xorg-x11-server: tigervnc: integer overflow in big requests extension

A flaw was found in the Big Requests extension. The request length is multiplied by 4 before checking against the maximum allowed size, potentially causing an integer overflow and bypassing the size check.

HighCVSS 7.3Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A local user can abuse a size-checking flaw in Xorg/Xwayland/TigerVNC components. The bug can let an oversized request pass validation, creating risk of data exposure, tampering, or service disruption on affected Red Hat systems.

Executive priority

Handle as high-priority Linux endpoint and remote desktop patching. Business risk is highest where many users share GUI-capable systems or where TigerVNC/Xwayland supports operational access.

Technical view

The Big Requests extension multiplies request length by 4 before enforcing the maximum allowed size. That arithmetic can overflow, bypassing the intended size check. CVSS 3.1 is 7.3 with local attack vector, low complexity, low privileges, no user interaction, and high integrity and availability impact.

Likely exposure

Exposure is most likely on affected Red Hat Enterprise Linux systems running xorg-x11-server, xorg-x11-server-Xwayland, or tigervnc packages, especially GUI, VDI, remote desktop, and shared Linux hosts.

Exploitation context

The source bundle does not show CISA KEV listing or cited active exploitation. The CVSS vector indicates exploitation requires local access and low privileges, but no user interaction.

Researcher notes

Evidence supports an integer overflow in Big Requests size validation. The bundle provides affected Red Hat package streams and advisories, but not exploit proof, exploit maturity, or fixed-version detail beyond advisory references.

Mitigation direction

  • Apply the relevant Red Hat RHSA updates for affected RHEL streams.
  • Check Red Hat guidance for fixed package versions before rollout.
  • Prioritize shared workstations, VDI, jump hosts, and TigerVNC systems.
  • Limit local account access on affected GUI or remote desktop hosts.
  • Retire unsupported or extended-life systems where updates are unavailable.

Validation and detection

  • Inventory installed xorg-x11-server, Xwayland, and tigervnc packages.
  • Compare package versions against the affected versions in the CVE record.
  • Confirm applicable Red Hat advisories are installed on each RHEL stream.
  • Review VDI and remote desktop images for stale vulnerable packages.
  • Document exceptions where vendor-fixed packages are not available.
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-190: 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.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2025-49176 mapping review

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

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.3 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/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.

1CVSS vectors
5Timeline events
2ADP providers
35Source links

SSVC decision data

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

CVSS vector scores

1 official score

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
7.3CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H1.85.5redhat

Vulnerability scoring details

Base CVSS 3.1 score

7.3High
CVSS 3.1 vector shape for CVE-2025-49176Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/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. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. Source timelineredhat

    Reported to Red Hat.

  3. Source timelineredhat

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

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

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
X.Orgxwaylandxwayland, 0unaffected
Red HatRed Hat Enterprise Linux 10xorg-x11-server-Xwayland, 0:24.1.5-4.el10_0affected
Red HatRed Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSIONtigervnc, 0:1.1.0-25.el6_10.1affected
Red HatRed Hat Enterprise Linux 7.7 Advanced Update Supporttigervnc, 0:1.8.0-17.el7_7.1affected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Supportxorg-x11-server, 0:1.20.4-32.el7_9affected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Supporttigervnc, 0:1.8.0-36.el7_9.2affected
Red HatRed Hat Enterprise Linux 8xorg-x11-server, 0:1.20.11-26.el8_10affected
Red HatRed Hat Enterprise Linux 8xorg-x11-server-Xwayland, 0:21.1.3-18.el8_10affected
Red HatRed Hat Enterprise Linux 8tigervnc, 0:1.15.0-7.el8_10affected
Red HatRed Hat Enterprise Linux 8.2 Advanced Update Supporttigervnc, 0:1.9.0-15.el8_2.14affected
Red HatRed Hat Enterprise Linux 8.2 Advanced Update Supportxorg-x11-server, 0:1.20.6-4.el8_2affected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Supportxorg-x11-server, 0:1.20.10-2.el8_4affected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Supporttigervnc, 0:1.11.0-8.el8_4.13affected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-Onxorg-x11-server, 0:1.20.10-2.el8_4affected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-Ontigervnc, 0:1.11.0-8.el8_4.13affected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Supporttigervnc, 0:1.12.0-6.el8_6.14affected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Supportxorg-x11-server-Xwayland, 0:21.1.3-2.el8_6.4affected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Supportxorg-x11-server, 0:1.20.11-5.el8_6.3affected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-Ontigervnc, 0:1.12.0-6.el8_6.14affected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-Onxorg-x11-server-Xwayland, 0:21.1.3-2.el8_6.4affected
Red HatRed Hat Enterprise Linux 8.6 Telecommunications Update Servicetigervnc, 0:1.12.0-6.el8_6.14affected
Red HatRed Hat Enterprise Linux 8.6 Telecommunications Update Servicexorg-x11-server-Xwayland, 0:21.1.3-2.el8_6.4affected
Red HatRed Hat Enterprise Linux 8.6 Telecommunications Update Servicexorg-x11-server, 0:1.20.11-5.el8_6.3affected
Red HatRed Hat Enterprise Linux 8.6 Update Services for SAP Solutionstigervnc, 0:1.12.0-6.el8_6.14affected
Red HatRed Hat Enterprise Linux 8.6 Update Services for SAP Solutionsxorg-x11-server-Xwayland, 0:21.1.3-2.el8_6.4affected
Red HatRed Hat Enterprise Linux 8.6 Update Services for SAP Solutionsxorg-x11-server, 0:1.20.11-5.el8_6.3affected
Red HatRed Hat Enterprise Linux 8.8 Extended Update Support Long-Life Add-Onxorg-x11-server, 0:1.20.11-16.el8_8affected
Red HatRed Hat Enterprise Linux 8.8 Extended Update Support Long-Life Add-Onxorg-x11-server-Xwayland, 0:21.1.3-11.el8_8affected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Servicexorg-x11-server, 0:1.20.11-16.el8_8affected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Servicetigervnc, 0:1.12.0-15.el8_8.14affected
Weakness

CWE details

CWE-190

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

CWE-190 · source CWE mapping

Integer Overflow or Wraparound

Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs