[UPDATE] [medium] X.Org X11 and Xwayland: Multiple vulnerabilities
An attacker can exploit multiple vulnerabilities in X.Org X11 and Xwayland to disclose information, escalate privileges, conduct a denial of service attack, and perform an unspecified attack.
CSIRTS triage
- What
- Multiple vulnerabilities allow an attacker to disclose information, escalate privileges, conduct a denial of service attack, and perform an unspecified attack.
- Who is affected
- Deployments of X.Org X11 and Xwayland are affected.
- Urgency
- Remediation is medium urgency due to the range of impacts possible.
- Action
- Update to the latest version of X.Org X11 and Xwayland.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-1774
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-502560.16% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 5% of all scored CVEs.
- Low exploitation riskCVE-2026-502570.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all scored CVEs.
- Low exploitation riskCVE-2026-502580.16% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 6% of all scored CVEs.
- Low exploitation riskCVE-2026-502590.17% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 6% of all scored CVEs.
- Low exploitation riskCVE-2026-502600.15% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 5% of all scored CVEs.
- Low exploitation riskCVE-2026-502610.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all scored CVEs.
- Low exploitation riskCVE-2026-502620.13% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all scored CVEs.
- Low exploitation riskCVE-2026-502630.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all scored CVEs.
- Low exploitation riskCVE-2026-502640.15% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-50256 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-50257 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-50258 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-50259 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-50260 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-50261 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-50262 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-50263 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-50264 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownDSA-6370-1 incus - security updatedebian
- mediumCVE-2026-50262: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: out-of-bounds read/write in glx ch…msrc
- mediumCVE-2026-50260: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in freecounter()msrc
- mediumCVE-2026-50257: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in misyncdestroyfen…msrc
- highCVE-2026-50256: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in font alia…msrc
- mediumCVE-2026-50263: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free information disclos…msrc
- highCVE-2026-50261: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in syncchangecounte…msrc
- highCVE-2026-50259: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in xkb setma…msrc
- highCVE-2026-50258: Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in xkb key t…msrc
Recent advisories for X.Org X11 and Xwayland
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- medium[UPDATE] [medium] X.Org X11, Xwayland: Multiple vulnerabilitiescert-bund · 2026-07-09
- high[UPDATE] [high] Xwayland and X.Org X11: Multiple vulnerabilities allow unspecified attackcert-bund · 2026-07-09
- medium[UPDATE] [medium] X.Org X11 and Xwayland: Multiple vulnerabilitiescert-bund · 2026-07-09
- high[NEW] [high] X.Org X11 and Xwayland: Multiple vulnerabilities allow code execution and DoScert-bund · 2026-07-09
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