CVE-2026-116137

Description

adm-zip through 0.6.1 contains a duplicate-entry validation bypass that allows attackers to evade the readEntries() check by using canonically equivalent entry names like './hello.txt' and 'hello.txt'. Attackers can craft ZIP archives where getEntry() or readAsText() validates benign content while extractAllTo() writes malicious content to the same path, bypassing integrity checks.

References

• https://github.com/cthackers/adm-zip
• https://github.com/cthackers/adm-zip/blob/cb2cf9ba4c7c865db426e2de1997cb41194d9872/adm-zip.js#L87
• https://github.com/cthackers/adm-zip/blob/cb2cf9ba4c7c865db426e2de1997cb41194d9872/util/utils.js#L383
• https://github.com/cthackers/adm-zip/blob/cb2cf9ba4c7c865db426e2de1997cb41194d9872/zipFile.js#L81-L92
• https://github.com/cthackers/adm-zip/issues/587