CVE-2026-48103
CVE-2026-48103 is a medium-severity vulnerability in 7-zip with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.
Key facts
- Severity: Medium (CVSS 3.x base score 4.3)
- EPSS exploit prediction: 0% (13th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-34852
- Weakness: CWE-125
- Affected product: 7-zip
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-48103?
- 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.
- How severe is CVE-2026-48103?
- CVE-2026-48103 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability low.
- Is CVE-2026-48103 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-48103?
- CVE-2026-48103 affects 7-zip. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-48103?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-48103 have an EU (EUVD) identifier?
- Yes. CVE-2026-48103 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34852.
- When was CVE-2026-48103 published?
- CVE-2026-48103 was published on 2026-06-05 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:7-zip:7-zip:*:*:*:*:*:*:*:*
More vulnerabilities in 7-zip
- CVE-2008-6536 — Critical (CVSS 10.0): Unspecified vulnerability in 7-zip before 4.5.7 has unknown impact and remote attack vectors, as demonstrated by the…
- CVE-2026-48095 — High (CVSS 8.8): 7-Zip is a file archiver with a high compression ratio. Versions 26.00 and prior contain a heap buffer overflow…
- CVE-2018-10172 — High (CVSS 8.8): 7-Zip through 18.01 on Windows implements the "Large memory pages" option by calling the LsaAddAccountRights function…
- CVE-2016-2335 — High (CVSS 8.8): The CInArchive::ReadFileItem method in Archive/Udf/UdfIn.cpp in 7zip 9.20 and 15.05 beta and p7zip allows remote…
- CVE-2025-11002 — High (CVSS 7.8): 7-Zip ZIP File Parsing Directory Traversal Remote Code Execution Vulnerability. This vulnerability allows remote…
- CVE-2025-11001 — High (CVSS 7.8): 7-Zip ZIP File Parsing Directory Traversal Remote Code Execution Vulnerability. This vulnerability allows remote…
Other CWE-125 (Out-of-bounds Read) vulnerabilities
- CVE-2026-24826 — Critical (CVSS 10.0): Out-of-bounds Write, Divide By Zero, NULL Pointer Dereference, Use of Uninitialized Resource, Out-of-bounds Read,…
- CVE-2024-22004 — Critical (CVSS 10.0): Due to length check, an attacker with privilege access on a Linux Nonsecure operating system can trigger a…
- CVE-2021-41556 — Critical (CVSS 10.0): sqclass.cpp in Squirrel through 2.2.5 and 3.x through 3.1 allows an out-of-bounds read (in the core interpreter) that…
- CVE-2021-21777 — Critical (CVSS 10.0): An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer…
- CVE-2017-14451 — Critical (CVSS 10.0): An exploitable out-of-bounds read vulnerability exists in libevm (Ethereum Virtual Machine) of CPP-Ethereum. A…
- CVE-2013-0767 — Critical (CVSS 10.0): The nsSVGPathElement::GetPathLengthScale function in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and…