CVE-2023-3138

A vulnerability was found in libX11. The security flaw occurs because the functions in src/InitExt.c in libX11 do not check that the values provided for the Request, Event, or Error IDs are within the bounds of the arrays that those functions write to, using those IDs as array indexes. They trust that they were called with values provided by an Xserver adhering to the bounds specified in the X11 protocol, as all X servers provided by X.Org do. As the protocol only specifies a single byte for these values, an out-of-bounds value provided by a malicious server (or a malicious proxy-in-the-middle) can only overwrite other portions of the Display structure and not write outside the bounds of the Display structure itself, possibly causing the client to crash with this memory corruption.

Published: 2023-06-28 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-3138 is rated Moderate Risk (56.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.67%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-3138

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-16 1.39% 1.67% +0.28%
2 2026-06-15 0.11% 1.39% +1.28%
3 2025-11-29 — 0.11% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-3138

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-3138

OS Trackers for CVE-2023-3138

vendor priority summary link
alpine — CVE-2023-3138: 1 source package rows (libx11); 22 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 2, open 20. https://security.alpinelinux.org/vuln/CVE-2023-3138
debian not yet assigned CVE-2023-3138 not yet assigned priority: Debian including 1 source packages (libx11), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-3138
gentoo normal CVE-2023-3138: 1 GLSA(s) (202407-21), 1 atom(s) (x11-libs/libX11); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-3138
redhat medium — https://access.redhat.com/security/cve/CVE-2023-3138
suse high CVE-2023-3138 severity important: SUSE including 290 source package names (11-6.9:libX11-6-1.6.5-150000.3.30.1, 11-6.9:libX11-data-1.6.5-150000.3.30.1, …), 814 product×package rows across 174 product lines (Container bci/openjdk, Container bci/openjdk-devel, … (174 product lines)): Fixed 583, Known Affected 231. https://www.suse.com/security/cve/CVE-2023-3138/
ubuntu medium CVE-2023-3138 medium priority: Ubuntu including 1 source packages (libx11), 8 status rows across 8 suites (bionic, focal, jammy, kinetic, lunar, trusty, upstream, xenial): released 8. https://ubuntu.com/security/CVE-2023-3138

Affected software / configurations for CVE-2023-3138

Vendor Product Version Raw CPE
x.org libx11 < 1.8.6 cpe:2.3:a:x.org:libx11:*:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*

References for CVE-2023-3138

cvelogic Threat Intelligence