# CVE-2026-14191 — RARLAB WinRAR

> As of 2026-07-09, CVE-2026-14191 is a HIGH-severity vulnerability in RARLAB WinRAR, CVSS v3.1 7.8, EPSS 0.4% (36.0th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-14191, most recently “WinRAR 7.23 Fixes Heap Overflow in RAR5 Recovery Volume Processing (CVE-2026-14191)”.

**Last updated:** 2026-07-09

## What is CVE-2026-14191?

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.

The record classifies CVE-2026-14191 under weakness classes [CWE-787](https://intel.threadlinqs.com/cwe/CWE-787), [CWE-129](https://cwe.mitre.org/data/definitions/129.html). Its CVSS v3 base vector states that the flaw requires local access to the host, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 4 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 106 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.8 — HIGH (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 36.0% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 7.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-01, last modified 2026-07-09

## Is CVE-2026-14191 being exploited?

Weaponised exploit code for CVE-2026-14191 is publicly available. 2 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 27 in the Threadlinqs vulnerability feed.

- [HORKimhab/CVE-2026-14191](https://github.com/HORKimhab/CVE-2026-14191) (github)
- [trickest/cve](https://github.com/trickest/cve/blob/main/2026/CVE-2026-14191.md) (trickest)

## Affected products and versions

- [RARLAB](https://intel.threadlinqs.com/vendors/rarlab): WinRAR, RAR, UnRAR, UnRAR.dll

## How to fix CVE-2026-14191

No vendor patch reference has been recorded for CVE-2026-14191 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-14191

1 tracked threat in the Threadlinqs corpus references CVE-2026-14191, either in the campaign’s CVE list or as an indicator on the campaign record.

- [WinRAR 7.23 Fixes Heap Overflow in RAR5 Recovery Volume Processing (CVE-2026-14191)](https://intel.threadlinqs.com/threat/TL-2026-1063) — MEDIUM · 2026-07-02

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-10-10. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [rarlab.com — patch](https://www.rarlab.com/download.htm)

**Other references**

- [nvd.nist.gov — related](https://nvd.nist.gov/vuln/detail/CVE-2023-40477)
- [securin.io](https://www.securin.io/zero-days/cve-2026-14191-winrar-unrar-rar5-recovery-volume-rev-out-of-bounds-heap-write-in-recvolumes5-readheader)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-14191
Full detection coverage and IOCs for threats exploiting CVE-2026-14191 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp