Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.44% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-14191High confidence
WinRAR / UnRAR RAR5 recovery-volume (.rev) out-of-bounds heap write in RecVolumes5::ReadHeader
RARLAB · WinRAR
7.8HighCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productHigh technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 4 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs RARLAB WinRAR and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 4 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Debian Security Tracker: 4 affected package states with no published fix
Distribution package intelligence
9 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Package result overrides the generic status
BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 4 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.
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.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | rar | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian trixietrixie · source | unrar-nonfree | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | rar | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | unrar-nonfree | Affected, no fix publishedDebian currently tracks this release as open. | Not published in this feed | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | rar | Vendor fix publishedDebian records a fixed source-package version for this release. | 2:7.23-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | unrar-nonfree | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:7.2.7-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | rar | Vendor fix publishedDebian records a fixed source-package version for this release. | 2:7.23-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | unrar-nonfree | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:7.2.7-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | unrar-nonfree | Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 4 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
An out-of-bounds heap write exists in the RAR5 recovery-volume (.rev) parser in WinRAR and UnRAR (RecVolumes5::ReadHeader in recvol5.cpp). The RecItems vector is sized only when the first .rev file in a set is processed; subsequent .rev files supply an independent RecNum value that is validated against that file's own TotalCount field but never against the actual size of RecItems. A crafted set of two or more .rev files can therefore write an attacker-controlled 32-bit value (the header's RevCRC field) to RecItems[RecNum] at an attacker-controlled offset up to 65534 * sizeof(RecVolItem) bytes past the allocation, corrupting adjacent heap objects. Triggering requires the victim to run a recovery/test operation on an attacker-supplied .rev set (for example 'unrar t x.part1.rev', WinRAR 'Repair archive', or auto-recovery when extracting a volume set with a missing .rar part). This is the RAR5-path sibling of CVE-2023-40477 (which was fixed in the RAR3 path only in WinRAR 6.23). Fixed in WinRAR / RAR 7.23.
What
An out-of-bounds heap write exists in the RAR5 recovery-volume (.rev) parser in WinRAR and UnRAR (RecVolumes5::ReadHeader in recvol5.cpp). The RecItems vector is sized only when the first .rev file in a set is processed; subsequent .rev files supply an independent RecNum value that is validated against that file's own TotalCount field but never against the actual size of RecItems. A crafted set of two or more .rev files can therefore write an attacker-controlled 32-bit value (the header's RevCRC field) to RecItems[RecNum] at an attacker-controlled offset up to 65534 * sizeof(RecVolItem) bytes past the allocation, corrupting adjacent heap objects. Triggering requires the victim to run a recovery/test operation on an attacker-supplied .rev set (for example 'unrar t x.part1.rev', WinRAR 'Repair archive', or auto-recovery when extracting a volume set with a missing .rar part). This is the RAR5-path sibling of CVE-2023-40477 (which was fixed in the RAR3 path only in WinRAR 6.23). Fixed in WinRAR / RAR 7.23.
Why
A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.
How
An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
An out-of-bounds heap write exists in the RAR5 recovery-volume (.rev) parser in WinRAR and UnRAR (RecVolumes5::ReadHeader in recvol5.cpp). The RecItems vector is sized only when the first .rev file in a set is processed; subsequent .rev files supply an independent RecNum value that is validated against that file's own TotalCount field but never against the actual size of RecItems. A crafted set of two or more .rev files can therefore write an attacker-controlled 32-bit value (the header's RevCRC field) to RecItems[RecNum] at an attacker-controlled offset up to 65534 * sizeof(RecVolItem) bytes past the allocation, corrupting adjacent heap objects. Triggering requires the victim to run a recovery/test operation on an attacker-supplied .rev set (for example 'unrar t x.part1.rev', WinRAR 'Repair archive', or auto-recovery when extracting a volume set with a missing .rar part). This is the RAR5-path sibling of CVE-2023-40477 (which was fixed in the RAR3 path only in WinRAR 6.23). Fixed in WinRAR / RAR 7.23.
Why
A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.
How
An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 → Out-of-bounds Write → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Local
- Privileges required
- None: unauthenticated exploitation is possible
- 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-787 ↗
CWE-787: Out-of-bounds Write. The product writes data past the end, or before the beginning, of the intended buffer.
- 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:N/UI:R/S:U/C:H/I:H/A:HCommon 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.PRNonePrivileges required: The attacker does not need an account or existing 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.IHighIntegrity impact: A successful attack can cause a major loss.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.
03
Patch and workaround
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. - Fix availability varies by product
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 1 Jul 2026 · Last source change 9 Jul 2026, 04:47 UTC · CWE-787 · Out-of-bounds Write
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-40869
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD not scheduled
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
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.