VulnerabilityDeferred

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).

HIGH 7.8EPSS 0.44%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.1: 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.44% probability · 37th percentile
CISA KEV: Not listed
Weakness: CWE-129, CWE-787
Source: 33c584b5-0579-4c06-b2a0-8d8329fcab9c

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.