Libarchive: heap buffer over read in copy_from_lzss_window() at archive_read_support_format_rar.c
Unknown · Unknown
6.6MediumCVSS 3.1
Recommended action
Scheduled
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available
Distribution package intelligence
Ubuntu vendor package status
Canonical’s release and source-package findings are shown separately from local repository availability.
1 package state
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
Ubuntu release
Source package
Vendor state
Fixed version
Evidence
Ubuntu 24.04 LTSnoble · standard archive
libarchive
Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
1 current
CVE-2025-5915 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitylibarchive: Heap buffer over read in copy_from_lzss_window() at archive_read_support_format_rar.c
22 known affected
The vendor explicitly identifies these products as affected by this CVE.
bsdtar as a component of Red Hat Enterprise Linux 10
libarchive as a component of Red Hat Enterprise Linux 10
libarchive-devel as a component of Red Hat Enterprise Linux 10
libarchive.src as a component of Red Hat Enterprise Linux 10
libarchive as a component of Red Hat Enterprise Linux 6
libarchive-devel as a component of Red Hat Enterprise Linux 6
libarchive.src as a component of Red Hat Enterprise Linux 6
bsdcpio as a component of Red Hat Enterprise Linux 7
bsdtar as a component of Red Hat Enterprise Linux 7
libarchive as a component of Red Hat Enterprise Linux 7
libarchive-devel as a component of Red Hat Enterprise Linux 7
libarchive.src as a component of Red Hat Enterprise Linux 7
Summary
A vulnerability has been identified in the libarchive library. This flaw can lead to a heap buffer over-read due to the size of a filter block potentially exceeding the Lempel-Ziv-Storer-Schieber (LZSS) window. This means the library may attempt to read beyond the allocated memory buffer, which can result in unpredictable program behavior, crashes (denial of service), or the disclosure of sensitive information from adjacent memory regions.
Remediation
Upgrade to libarchive version 3.8.0 or later, which includes important security fixes and stability improvements.
Optional official sources
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.
Official European source
ENISA European Vulnerability Database
Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.
1 current
ENISA EUVD identifier
EUVD-2025-17576
No EUVD known-exploited evidence
A vulnerability has been identified in the libarchive library. This flaw can lead to a heap buffer over-read due to the size of a filter block potentially exceeding the Lempel-Ziv-Storer-Schieber (LZSS) window. This means the library may attempt to read beyond the allocated memory buffer, which can result in unpredictable program behavior, crashes (denial of service), or the disclosure of sensitive information from adjacent memory regions.
EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
6.6 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available
01
What, why and how
A vulnerability has been identified in the libarchive library. This flaw can lead to a heap buffer over-read due to the size of a filter block potentially exceeding the Lempel-Ziv-Storer-Schieber (LZSS) window. This means the library may attempt to read beyond the allocated memory buffer, which can result in unpredictable program behavior, crashes (denial of service), or the disclosure of sensitive information from adjacent memory regions.
What
A vulnerability has been identified in the libarchive library. This flaw can lead to a heap buffer over-read due to the size of a filter block potentially exceeding the Lempel-Ziv-Storer-Schieber (LZSS) window. This means the library may attempt to read beyond the allocated memory buffer, which can result in unpredictable program behavior, crashes (denial of service), or the disclosure of sensitive information from adjacent memory regions.
Why
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may obtain information outside the intended access boundary.
What
A vulnerability has been identified in the libarchive library. This flaw can lead to a heap buffer over-read due to the size of a filter block potentially exceeding the Lempel-Ziv-Storer-Schieber (LZSS) window. This means the library may attempt to read beyond the allocated memory buffer, which can result in unpredictable program behavior, crashes (denial of service), or the disclosure of sensitive information from adjacent memory regions.
Why
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may obtain information outside the intended access boundary.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No confirmed evidence
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.None recorded
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
Likely attack path
local access → Heap-based Buffer Overflow → obtain information outside the intended access boundary
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-122: Heap-based Buffer Overflow. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:H
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
Denial of serviceCWE-122
A
Official authority intelligence
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2025-17576Official EUVD mapping
A vulnerability has been identified in the libarchive library. This flaw can lead to a heap buffer over-read due to the size of a filter block potentially exceeding the Lempel-Ziv-Storer-Schieber (LZSS) window. This means the library may attempt to read beyond the allocated memory buffer, which can result in unpredictable program behavior, crashes (denial of service), or the disclosure of sensitive information from adjacent memory regions.
Official EUVD recordCERT-FR · French · CERTFR-2026-AVI-0266Multiples vulnérabilités dans VMware Tanzu
Operational remediation based on structured source evidence.
Status ?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
bsdtar as a component of Red Hat Enterprise Linux 10; libarchive as a component of Red Hat Enterprise Linux 10; libarchive-devel as a component of Red Hat Enterprise Linux 10; libarchive.src as a component of Red Hat Enterprise Linux 10; libarchive as a component of Red Hat Enterprise Linux 6; libarchive-devel as a component of Red Hat Enterprise Linux 6; libarchive.src as a component of Red Hat Enterprise Linux 6; bsdcpio as a component of Red Hat Enterprise Linux 7; bsdtar as a component of Red Hat Enterprise Linux 7; libarchive as a component of Red Hat Enterprise Linux 7; libarchive-devel as a component of Red Hat Enterprise Linux 7; libarchive.src as a component of Red Hat Enterprise Linux 7; bsdtar as a component of Red Hat Enterprise Linux 8; libarchive as a component of Red Hat Enterprise Linux 8; libarchive-devel as a component of Red Hat Enterprise Linux 8; libarchive.src as a component of Red Hat Enterprise Linux 8; bsdtar as a component of Red Hat Enterprise Linux 9; libarchive as a component of Red Hat Enterprise Linux 9; libarchive-devel as a component of Red Hat Enterprise Linux 9; libarchive.src as a component of Red Hat Enterprise Linux 9; openshift/ose-rhel-coreos-8 as a component of Red Hat OpenShift Container Platform 4; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
Upgrade to libarchive version 3.8.0 or later, which includes important security fixes and stability improvements.
04
Evidence and provenance
Published 9 Jun 2025 · Last source change 1 Sept 2026, 12:08 UTC · CWE-122 · Heap-based Buffer Overflow
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source ?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-17576
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Affected versionsThe structured affected or fixed version information changed.
Before
bsdtar as a component of Red Hat Enterprise Linux 10; libarchive as a component of Red Hat Enterprise Linux 10; libarchive-devel as a component of Red Hat Enterprise Linux 10; libarchive.src as a component of Red Hat Enterprise Linux 10; libarchive as a component of Red Hat Enterprise Linux 6; libarchive-devel as a component of Red Hat Enterprise Linux 6; libarchive.src as a component of Red Hat Enterprise Linux 6; bsdcpio as a component of Red Hat Enterprise Linux 7; bsdtar as a component of Red Hat Enterprise Linux 7; libarchive as a component of Red Hat Enterprise Linux 7; libarchive-devel as a component of Red Hat Enterprise Linux 7; libarchive.src as a component of Red Hat Enterprise Linux 7; bsdtar as a component of Red Hat Enterprise Linux 8; libarchive as a component of Red Hat Enterprise Linux 8; libarchive-devel as a component of Red Hat Enterprise Linux 8; libarchive.src as a component of Red Hat Enterprise Linux 8; bsdtar as a component of Red Hat Enterprise Linux 9; libarchive as a component of Red Hat Enterprise Linux 9; libarchive-devel as a component of Red Hat Enterprise Linux 9; libarchive.src as a component of Red Hat Enterprise Linux 9; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4
After
bsdtar as a component of Red Hat Enterprise Linux 10; libarchive as a component of Red Hat Enterprise Linux 10; libarchive-devel as a component of Red Hat Enterprise Linux 10; libarchive.src as a component of Red Hat Enterprise Linux 10; libarchive as a component of Red Hat Enterprise Linux 6; libarchive-devel as a component of Red Hat Enterprise Linux 6; libarchive.src as a component of Red Hat Enterprise Linux 6; bsdcpio as a component of Red Hat Enterprise Linux 7; bsdtar as a component of Red Hat Enterprise Linux 7; libarchive as a component of Red Hat Enterprise Linux 7; libarchive-devel as a component of Red Hat Enterprise Linux 7; libarchive.src as a component of Red Hat Enterprise Linux 7; bsdtar as a component of Red Hat Enterprise Linux 8; libarchive as a component of Red Hat Enterprise Linux 8; libarchive-devel as a component of Red Hat Enterprise Linux 8; libarchive.src as a component of Red Hat Enterprise Linux 8; bsdtar as a component of Red Hat Enterprise Linux 9; libarchive as a component of Red Hat Enterprise Linux 9; libarchive-devel as a component of Red Hat Enterprise Linux 9; libarchive.src as a component of Red Hat Enterprise Linux 9; openshift/ose-rhel-coreos-8 as a component of Red Hat OpenShift Container Platform 4; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
CVE-2025-5915: Libarchive: heap buffer over read in copy_from_lzss_window() at archive_read_support_format_rar.c | BlackTree
