Vulnerability in Tigervnc
CVE-2025-26599
An access to an uninitialized pointer flaw was found in X.Org and Xwayland. The function compCheckRedirect() may fail if it cannot allocate the backing pixmap. In that case, compRedirectWindow() will return a BadAlloc error without validating the window tree marked just before, which leaves the validated data partly initialized and the use of an uninitialized pointer later.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (33.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Tigervnc
- X.org X Server
- X.org Xwayland
- Red Hat Enterprise Linux 10 — versions 0:24.1.5-3.el10_0
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 6 Extended Lifecycle Support - Extension — versions 0:1.1.0-25.el6_10
- Red Hat Enterprise Linux 7 Extended Lifecycle Support — versions 0:1.8.0-36.el7_9, 0:1.20.4-30.el7_9
- Red Hat Enterprise Linux 8 — versions 0:1.13.1-15.el8_10
- Red Hat Enterprise Linux 8.2 Advanced Update Support — versions 0:1.9.0-15.el8_2.13
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support — versions 0:1.11.0-8.el8_4.12
Weakness classification (CWE)
Public proof-of-concept exploits
References
- access.redhat.com/errata/RHSA-2025:2500 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2025:2502 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2025:2861 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2025:2862 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2025:2865 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2025:2866 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2025:2873 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2025:2874 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2025:2875 (vendor-advisory, Third Party Advisory)
- access.redhat.com/errata/RHSA-2025:2879 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2025-26599?
- CVE-2025-26599 is a high-severity vulnerability in Tigervnc, classified under Access of Uninitialized Pointer. CVSS score: 7.8/10. Published 2025-02-25.
- How severe is CVE-2025-26599?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2025-26599 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.