# RHSA-2026:28923: Security update for 7 packages

RHSA-2026:28923, released June 25, 2026, fixes 9 CVEs across 7 products. None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/linux/rhsa-2026-28923
- Platform: Linux
- Released: Jun 25, 2026
- Priority: High (Closes CVE-2026-50259, high severity)
- CVEs: 9, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://access.redhat.com/errata/RHSA-2026:28923

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [tigervnc](https://patchblox.com/security/data/product/linux/tigervnc.md) | RHEL 8 | 0:1.15.0-10.el8_10 |
| [tigervnc-icons](https://patchblox.com/security/data/product/linux/tigervnc-icons.md) | RHEL 8 | 0:1.15.0-10.el8_10 |
| [tigervnc-license](https://patchblox.com/security/data/product/linux/tigervnc-license.md) | RHEL 8 | 0:1.15.0-10.el8_10 |
| [tigervnc-selinux](https://patchblox.com/security/data/product/linux/tigervnc-selinux.md) | RHEL 8 | 0:1.15.0-10.el8_10 |
| [tigervnc-server](https://patchblox.com/security/data/product/linux/tigervnc-server.md) | RHEL 8 | 0:1.15.0-10.el8_10 |
| [tigervnc-server-minimal](https://patchblox.com/security/data/product/linux/tigervnc-server-minimal.md) | RHEL 8 | 0:1.15.0-10.el8_10 |
| [tigervnc-server-module](https://patchblox.com/security/data/product/linux/tigervnc-server-module.md) | RHEL 8 | 0:1.15.0-10.el8_10 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2026-50259](https://patchblox.com/security/data/cve/CVE-2026-50259.md) | High | Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in xkb setmap request via mapwidths indexing | 7.8 | 0.0017 |  |
| [CVE-2026-50258](https://patchblox.com/security/data/cve/CVE-2026-50258.md) | High | Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in xkb key types due to unchecked shift levels | 7.8 | 0.0016 |  |
| [CVE-2026-50256](https://patchblox.com/security/data/cve/CVE-2026-50256.md) | High | Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libxfont2 name length mismatch | 7.8 | 0.0016 |  |
| [CVE-2026-50260](https://patchblox.com/security/data/cve/CVE-2026-50260.md) | High | Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in freecounter() | 7.8 | 0.0015 |  |
| [CVE-2026-50261](https://patchblox.com/security/data/cve/CVE-2026-50261.md) | High | Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in syncchangecounter() | 7.8 | 0.0015 |  |
| [CVE-2026-50264](https://patchblox.com/security/data/cve/CVE-2026-50264.md) | High | xorg-server: An out-of-bounds write flaw was found in the X.Org X server and Xwayland in DRIGetBuffers/DRIGetBuffersWithFormat | 7.8 | 0.0015 |  |
| [CVE-2026-50257](https://patchblox.com/security/data/cve/CVE-2026-50257.md) | High | Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in misyncdestroyfence() | 7.8 | 0.0014 |  |
| [CVE-2026-50263](https://patchblox.com/security/data/cve/CVE-2026-50263.md) | High | Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free information disclosure in createsaverwindow() | 7.8 | 0.0014 |  |
| [CVE-2026-50262](https://patchblox.com/security/data/cve/CVE-2026-50262.md) | High | Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: out-of-bounds read/write in glx changedrawableattributes | 7.8 | 0.0013 |  |

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Data as of 2026-11-07T18:46:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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