4.3
MEDIUM CVSS 3.1
CVE-2026-48103
GHSL-2026-119 7-Zip WIM SecurityId OOB read
Description

7-Zip is a file archiver with a high compression ratio. Versions 9.34 through 26.00 contain an off-by-one heap out-of-bounds read in the WIM (Windows Imaging) archive handler's security descriptor lookup. In CHandler::GetSecurity (CPP/7zip/Archive/Wim/WimHandler.cpp), the per-image SecurOffsets table holds numEntries + 1 cumulative offsets, but the check securityId >= SecurOffsets.Size() admits securityId == numEntries, and the function then reads SecurOffsets[securityId + 1], fetching one UInt32 past the end of the heap-allocated CRecordVector (which performs no bounds checking on operator[]). The securityId is attacker-controlled at offset +0xC of any directory entry in WIM metadata, and the handler is registered for .wim, .swm, .esd, and .ppkg and enabled by default in stock 7z.dll; the OOB triggers zero-click in the GUI because 7zFM.exe's ListView calls GetRawProp(kpidNtSecure) for every item during listing (ASan-confirmed), and is also reachable via CLI listing with 7zz l -slt. Impact is limited to denial of service under hardened allocators and minor information disclosure, since the OOB value is only consumed arithmetically as a length and is not surfaced to the attacker; there is no write primitive.

INFO

Published Date :

June 5, 2026, 5:16 p.m.

Last Modified :

June 5, 2026, 5:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-48103 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Apply updates to the 7-Zip file archiver to fix a heap out-of-bounds read vulnerability in the WIM handler.
  • Update 7-Zip to a version that addresses the WIM handler vulnerability.
  • Ensure the WIM archive handler is configured securely.
  • Limit the processing of untrusted WIM files.
  • Avoid opening WIM archives from unknown sources.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-48103.

URL Resource
https://securitylab.github.com/advisories/GHSL-2026-115_GHSL-2026-122_7-zip/
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-48103 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-48103 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-48103 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-48103 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jun. 05, 2026

    Action Type Old Value New Value
    Added Description 7-Zip is a file archiver with a high compression ratio. Versions 9.34 through 26.00 contain an off-by-one heap out-of-bounds read in the WIM (Windows Imaging) archive handler's security descriptor lookup. In CHandler::GetSecurity (CPP/7zip/Archive/Wim/WimHandler.cpp), the per-image SecurOffsets table holds numEntries + 1 cumulative offsets, but the check securityId >= SecurOffsets.Size() admits securityId == numEntries, and the function then reads SecurOffsets[securityId + 1], fetching one UInt32 past the end of the heap-allocated CRecordVector (which performs no bounds checking on operator[]). The securityId is attacker-controlled at offset +0xC of any directory entry in WIM metadata, and the handler is registered for .wim, .swm, .esd, and .ppkg and enabled by default in stock 7z.dll; the OOB triggers zero-click in the GUI because 7zFM.exe's ListView calls GetRawProp(kpidNtSecure) for every item during listing (ASan-confirmed), and is also reachable via CLI listing with 7zz l -slt. Impact is limited to denial of service under hardened allocators and minor information disclosure, since the OOB value is only consumed arithmetically as a length and is not surfaced to the attacker; there is no write primitive.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
    Added CWE CWE-125
    Added Reference https://securitylab.github.com/advisories/GHSL-2026-115_GHSL-2026-122_7-zip/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.