CVE-2026-48111
Versions 9.21 through 26.00 contain an off-by-one out-of-bounds read vulnerability in the ParseDepedencyExpression function of the UEFI firmware image parser(CPP/7zip/Archive/UefiHandler.cpp).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.22%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
7-Zip is a file archiver with a high compression ratio. Versions 9.21 through 26.00 contain an off-by-one out-of-bounds read vulnerability in the ParseDepedencyExpression function of the UEFI firmware image parser(CPP/7zip/Archive/UefiHandler.cpp). The function validates an attacker-controlled opcode byte using > instead of >= against the element count of the 10-entry kExpressionCommands static array, allowing an opcode value of 10 to read one pointer slot (8 bytes on x64) past the end of the array in .rodata. The out-of-bounds value is then dereferenced as a const char * and passed through strlen and memcpy into the archive's Characts property, which may cause either a denial of service (access violation when the adjacent bytes do not form a valid readable pointer) or a minor information disclosure of an adjacent .rdata string literal into archive metadata. The vulnerability is reached automatically during IInArchive::Open() via the call path OpenFv/OpenCapsule → ParseVolume → ParseSections when processing a SECTION_DXE_DEPEX (0x13) or SECTION_PEI_DEPEX (0x1B) section whose first body byte is 0x0A, and the UEFI handler is enabled by default in stock 7z.dll with signature-based detection for both UEFIc and UEFIf formats. The outcome (crash vs. silent leak) is deterministic per build but linker-layout dependent, with no write primitive and no disclosure of heap data, secrets, or ASLR base addresses. Version 26.01 fixes the issue.
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
- EPSS
- 0.22% probability · 13th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- 7-zip/7-zip
- Source
- security-advisories@github.com
References
- https://securitylab.github.com/advisories/GHSL-2026-115_GHSL-2026-122_7-zip/Exploit, Patch, Third Party Advisory
- https://securitylab.github.com/advisories/GHSL-2026-115_GHSL-2026-122_7-zip/Exploit, Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.