Buffer overflow in Tigervnc
CVE-2025-26597
A buffer overflow flaw was found in X.Org and Xwayland. If XkbChangeTypesOfKey() is called with a 0 group, it will resize the key symbols table to 0 but leave the key actions unchanged. If the same function is later called with a non-zero value of groups, this will cause a buffer overflow because the key actions are of the wrong size.
Vulnerability class: Buffer Overflow
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 (37.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.2% 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-2025-26597?
- CVE-2025-26597 is a high-severity vulnerability in Tigervnc, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.8/10. Published 2025-02-25.
- How severe is CVE-2025-26597?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2025-26597 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.