CVE-2026-4424 | Libarchive: libarchive: information disclosure via heap out-of-bounds read in rar archive processing

A flaw was found in libarchive. This heap out-of-bounds read vulnerability exists in the RAR archive processing logic due to improper validation of the LZSS sliding window size after transitions between compression methods. A remote attacker can exploit this by providing a specially crafted RAR archive, leading to the disclosure of sensitive heap memory information without requiring authentication or user interaction.

Published: 2026-03-19 Last update: 2026-06-10 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-4424 is rated Moderate Risk (49.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.88%). Mandatory action: 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-2026-4424

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 2026-06-15 0.10% 0.88% +0.78%
2 2026-05-26 0.16% 0.10% -0.06%
3 2026-05-22 0.16%

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-4424

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:H/I:N/A:N 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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-4424

GitHub Security Advisory for CVE-2026-4424

GHSA-c75f-55f6-f63q · Severity: high — A flaw was found in libarchive. This heap out-of-bounds read vulnerability exists in the RAR...

OS Trackers for CVE-2026-4424

vendor priority summary link
debian not yet assigned CVE-2026-4424 not yet assigned priority: Debian including 1 source packages (libarchive), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-4424
redhat high https://access.redhat.com/security/cve/CVE-2026-4424
suse high https://www.suse.com/security/cve/CVE-2026-4424/
ubuntu medium CVE-2026-4424 medium priority: Ubuntu including 1 source packages (libarchive), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): deferred 7, needs-triage 1. https://ubuntu.com/security/CVE-2026-4424

Affected software / configurations for CVE-2026-4424

Vendor Product Version Raw CPE
libarchive libarchive cpe:2.3:a:libarchive:libarchive:-:*:*:*:*:*:*:*
redhat hardened_images cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:*
redhat openshift_container_platform 4.0 cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*
redhat openshift_container_platform 4.16 cpe:2.3:a:redhat:openshift_container_platform:4.16:*:*:*:*:*:*:*
redhat openshift_container_platform_for_arm64 4.16 cpe:2.3:a:redhat:openshift_container_platform_for_arm64:4.16:*:*:*:*:*:*:*
redhat openshift_container_platform_for_power 4.16 cpe:2.3:a:redhat:openshift_container_platform_for_power:4.16:*:*:*:*:*:*:*
redhat enterprise_linux 6.0 cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*
redhat enterprise_linux 10.0 cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.2 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.4 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:*

References for CVE-2026-4424

URL Tags
https://access.redhat.com/errata/RHSA-2026:10065 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:10097 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:11768 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:12071
https://access.redhat.com/errata/RHSA-2026:12274
https://access.redhat.com/errata/RHSA-2026:13812
https://access.redhat.com/errata/RHSA-2026:14773
https://access.redhat.com/errata/RHSA-2026:14937
https://access.redhat.com/errata/RHSA-2026:15087
https://access.redhat.com/errata/RHSA-2026:16008
https://access.redhat.com/errata/RHSA-2026:16009
https://access.redhat.com/errata/RHSA-2026:16030
https://access.redhat.com/errata/RHSA-2026:16174
https://access.redhat.com/errata/RHSA-2026:17596
https://access.redhat.com/errata/RHSA-2026:19724
https://access.redhat.com/errata/RHSA-2026:19725
https://access.redhat.com/errata/RHSA-2026:20040
https://access.redhat.com/errata/RHSA-2026:21690
https://access.redhat.com/errata/RHSA-2026:25096
https://access.redhat.com/errata/RHSA-2026:8492 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8510 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8517 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8521 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8534 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8864 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8865 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8866 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8867 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8873 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8908 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:8944 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:9026 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:9592 Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:9832 Third Party Advisory
https://access.redhat.com/security/cve/CVE-2026-4424 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2449006 Issue Tracking Third Party Advisory
https://github.com/libarchive/libarchive/pull/2898 Issue Tracking Third Party Advisory
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