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CVE Record

CVE-2025-49179: Xorg-x11-server-xwayland: xorg-x11-server: tigervnc: integer overflow in x record extension

A flaw was found in the X Record extension. The RecordSanityCheckRegisterClients function does not check for an integer overflow when computing request length, which allows a client to bypass length checks.

HighCVSS 7.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2025-49179 is a high-severity flaw in the X Record extension used by Xorg/Xwayland and TigerVNC packages. A logged-in local client can bypass request length checks through an integer overflow. The source data indicates high confidentiality and availability impact, but does not show confirmed active exploitation.

Executive priority

Handle through an accelerated patch cycle for affected Linux graphical and VNC systems. It is not shown as internet-scale or actively exploited in the supplied sources, but the potential confidentiality and availability impact justifies high priority in shared-user environments.

Technical view

RecordSanityCheckRegisterClients fails to check integer overflow while computing request length. That can let a client bypass length validation in the X Record extension. The CVSS vector is local, low complexity, low privileges, no user interaction, with high confidentiality and availability impact.

Likely exposure

Exposure is most likely on affected Red Hat Enterprise Linux systems with xorg-x11-server, xorg-x11-server-Xwayland, or tigervnc installed, especially shared graphical desktops, VNC environments, and systems where untrusted local users can start X clients.

Exploitation context

The provided data does not identify public exploit code or active exploitation, and KEV is false. The attack requires local client access with low privileges, so the practical risk rises in multi-user Linux, remote desktop, lab, and shared administrative environments.

Researcher notes

Evidence is strongest for Red Hat-packaged xorg-x11-server, Xwayland, and TigerVNC. The bundle lists X.Org xwayland defaultStatus as unaffected, while many Red Hat package builds are affected. Do not infer other distributions or exploitability beyond the supplied sources.

Mitigation direction

  • Apply the relevant Red Hat security advisories for affected packages.
  • Prioritize shared Linux desktops, VNC hosts, and systems with untrusted local users.
  • Update xorg-x11-server, xorg-x11-server-Xwayland, and tigervnc where affected.
  • If patches are unavailable, check Red Hat guidance for supported compensating controls.
  • Limit graphical or VNC access to trusted users until remediation is complete.

Validation and detection

  • Inventory installed Xorg, Xwayland, and TigerVNC package versions.
  • Compare installed versions with the CVE record and applicable RHSA advisories.
  • Confirm updated packages are installed on affected RHEL releases and add-ons.
  • Identify systems offering shared graphical sessions or TigerVNC access.
  • Track vendor advisory updates because affected-product evidence may change.
Prepared
Confidence
medium
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.

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cve · low confidence lookup

CVE-2025-49179 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
7.3 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/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
34Source 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:H/I:L/A:H1.85.5redhat

Vulnerability scoring details

Base CVSS 3.1 score

7.3High
CVSS 3.1 vector shape for CVE-2025-49179Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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