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, CWE-129. 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 (github)
- trickest/cve (trickest)
Affected products and versions
- 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) — MEDIUM · 2026-07-02
Sources
Enriched from CVE.org, NVD, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.