Security readout for executives and security teams
Plain-English summary
CVE-2025-49177 is a local data-leak flaw in the XFIXES extension used by Xorg/Xwayland-related components. A logged-in local client could cause unintended memory from prior requests to be disclosed. The main business concern is exposure of sensitive desktop-session data on multi-user, VDI, or remote graphical systems.
Executive priority
Treat this as a scheduled but real confidentiality issue. It is not presented as internet-remote or actively exploited, but shared Linux graphical systems and remote desktop infrastructure should be patched promptly because leaked memory could contain sensitive user-session data.
Technical view
The XFixesSetClientDisconnectMode request handler does not validate request length. This can let a local, low-privileged client read unintended server memory from previous requests. Red Hat rates it medium with CVSS 6.1, reflecting high confidentiality impact, no integrity impact, and low availability impact.
Likely exposure
Exposure is most likely on Red Hat Enterprise Linux systems running affected xorg-x11-server, xorg-x11-server-Xwayland, or tigervnc packages, especially shared graphical environments, VNC hosts, jump boxes, and Linux desktops with multiple local users.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. The CVSS vector is local, low complexity, low privilege, and no user interaction, so exploitation depends on local access to an affected graphical server context.
Researcher notes
Evidence supports an out-of-bounds style information disclosure caused by missing request-length validation in XFIXES handling. The provided data identifies Red Hat package impact and upstream xserver commit reference, but does not provide exploit maturity, full downstream fixed-version mapping, or non-Red Hat distribution status.
Mitigation direction
- Apply the relevant Red Hat security errata for affected RHEL versions.
- Update xorg-x11-server, xorg-x11-server-Xwayland, and tigervnc packages where installed.
- Restrict access to local X/VNC sessions to trusted users only.
- Check vendor guidance for unsupported, EUS, or derivative distributions.
- Prioritize systems handling sensitive desktop sessions or shared remote access.
Validation and detection
- Inventory installed xorg-x11-server, Xwayland, and tigervnc packages across Linux fleets.
- Match package versions against Red Hat CVE and errata applicability.
- Confirm patched packages are deployed after maintenance.
- Review endpoint and VNC access controls for untrusted local users.
- Track vendor advisories for updated package status or regressions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-200: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. 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 lookupCVE-2025-49177 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
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.
SSVC decision data
CVSS vector scores
1 official scoreWe 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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L1.84.2redhatVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- Source timelineredhat
Reported to Red Hat.
- Source timelineredhat
Made public.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- RHSA-2025:10258CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2025:9303CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2025:9304CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2025-49177CVE reference, redhat · vdb-entry, x_refsource_REDHAT
- RHBZ#2369955CVE reference, redhat · issue-tracking, x_refsource_REDHAT
- https://gitlab.freedesktop.org/xorg/xserver/-/commit/ab02fb96b1c701c3bb47617d965522c34befa6afCVE reference, redhat
- https://www.x.org/wiki/Development/Security/CVE reference, redhat
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Exposure of Sensitive Information to an Unauthorized Actor
Exposure of Sensitive Information to an Unauthorized Actor represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.