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NVD / CVE Program· CNA redhat

CVE-2023-43785: Libx11: out-of-bounds memory access in _xkbreadkeysyms()

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.66% (FIRST EPSS); higher than 51.8% of all records.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: gitlab.freedesktop.org/xorg/lib/libx11 libX11 1.8.7.

Low priority for now. Upgrade to gitlab.freedesktop.org/xorg/lib/libx11 libX11 1.8.7 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A vulnerability was found in libX11 due to a boundary condition within the _XkbReadKeySyms() function. This flaw allows a local user to trigger an out-of-bounds read error and read the contents of memory on the system.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Oct 10, 2023
Updated
Jun 17, 2026
EPSS
0.6% · 51th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · redhat
6.5
1.0 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-43785

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
x.orglibx11
redhatenterprise linux
fedoraprojectfedora

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • fedoraproject fedora38
  • redhat enterprise linux8.0
  • redhat enterprise linux9.0
  • x.org libx11before 1.8.7

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • gitlab.freedesktop.org/xorg/lib/libx11 libX11

    • before 1.8.7affected · semver

  • Red Hat Red Hat Enterprise Linux 6

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 7

    • all versionsunknown

  • Red Hat Red Hat Enterprise Linux 8

    • 0:1.6.8-8.el8 and laternot affected · rpm

  • Red Hat Red Hat Enterprise Linux 9

    • 0:1.7.0-9.el9 and laternot affected · rpm

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8libX11before 1.6.8-8.el81.6.8-8.el8
AlmaLinux:8libX11-commonbefore 1.6.8-8.el81.6.8-8.el8
AlmaLinux:8libX11-develbefore 1.6.8-8.el81.6.8-8.el8
AlmaLinux:8libX11-xcbbefore 1.6.8-8.el81.6.8-8.el8
AlmaLinux:9libX11before 1.7.0-9.el91.7.0-9.el9
AlmaLinux:9libX11-commonbefore 1.7.0-9.el91.7.0-9.el9
AlmaLinux:9libX11-develbefore 1.7.0-9.el91.7.0-9.el9
AlmaLinux:9libX11-xcbbefore 1.7.0-9.el91.7.0-9.el9
Alpine:v3.16libx11before 1.8.7-r01.8.7-r0
Debian:10libx11before 2:1.6.7-1+deb10u42:1.6.7-1+deb10u4
Debian:11libx11before 2:1.7.2-1+deb11u22:1.7.2-1+deb11u2
Debian:12libx11before 2:1.8.4-2+deb12u22:1.8.4-2+deb12u2
Debian:13libx11before 2:1.8.7-12:1.8.7-1
openSUSE:Leap 15.4libX11before 1.6.5-150000.3.33.11.6.5-150000.3.33.1
Red Hat:enterprise_linux:8::appstreamlibX11before 0:1.6.8-8.el80:1.6.8-8.el8
Red Hat:enterprise_linux:8::appstreamlibX11-commonbefore 0:1.6.8-8.el80:1.6.8-8.el8
Red Hat:enterprise_linux:8::appstreamlibX11-debuginfobefore 0:1.6.8-8.el80:1.6.8-8.el8
Red Hat:enterprise_linux:8::appstreamlibX11-debugsourcebefore 0:1.6.8-8.el80:1.6.8-8.el8
Red Hat:enterprise_linux:8::appstreamlibX11-develbefore 0:1.6.8-8.el80:1.6.8-8.el8
Red Hat:enterprise_linux:8::appstreamlibX11-xcbbefore 0:1.6.8-8.el80:1.6.8-8.el8
Red Hat:enterprise_linux:8::appstreamlibX11-xcb-debuginfobefore 0:1.6.8-8.el80:1.6.8-8.el8
Red Hat:enterprise_linux:9::appstreamlibX11before 0:1.7.0-9.el90:1.7.0-9.el9
Red Hat:enterprise_linux:9::appstreamlibX11-commonbefore 0:1.7.0-9.el90:1.7.0-9.el9
Red Hat:enterprise_linux:9::appstreamlibX11-debuginfobefore 0:1.7.0-9.el90:1.7.0-9.el9

+8

Same product

x.org: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-31535LookupCol.c in X.Org X through X11R7.7 and libX11 before 1.7.1 might allow remote attackers to execute arbitrary code.
    42Plan
  • CVE-2018-14600An issue was discovered in libX11 through 1.6.5.
    42Plan
  • CVE-2018-14599An issue was discovered in libX11 through 1.6.5.
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2020-14363Sep 11, 2020 · An integer overflow vulnerability leading to a double-free was found in libX11.
    31Monitor
  • ← EarlierCVE-2023-3138Jun 28, 2023 · A vulnerability was found in libX11.
    30Monitor
  • Later →CVE-2023-43786Oct 10, 2023 · Libx11: stack exhaustion from infinite recursion in putsubimage()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
gitlab.freedesktop.org/xorg/lib/libx11 libX111.8.7Vendor (CNA)
almalinux:libX111.7.0-9.el9 · AlmaLinux:9Package registry (OSV)
almalinux:libX11-common1.7.0-9.el9 · AlmaLinux:9Package registry (OSV)
almalinux:libX11-devel1.7.0-9.el9 · AlmaLinux:9Package registry (OSV)
almalinux:libX11-xcb1.7.0-9.el9 · AlmaLinux:9Package registry (OSV)
alpine:libx111.8.7-r0 · Alpine:v3.16Package registry (OSV)
debian:libx112:1.8.4-2+deb12u2 · Debian:12Package registry (OSV)
opensuse:libX111.6.5-150000.3.33.1 · openSUSE:Leap 15.4Package registry (OSV)
red hat:libX110:1.7.0-9.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:libX11-common0:1.7.0-9.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:libX11-debuginfo0:1.7.0-9.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:libX11-debugsource0:1.7.0-9.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:libX11-devel0:1.7.0-9.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:libX11-xcb0:1.7.0-9.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:libX11-xcb-debuginfo0:1.7.0-9.el9 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
rocky linux:libX110:1.7.0-9.el9 · Rocky Linux:9Package registry (OSV)
suse:libX111.6.5-150000.3.33.1 · SUSE:Linux Enterprise Micro 5.3Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records