{"id":"CVE-2026-44722","aliases":["GHSA-crqm-m339-7m2p","PYSEC-2026-3044"],"url":"https://o3.security/vulnerability/CVE-2026-44722","summary":"pyzipper: Encryption bypass for small files encrypted with pyzipper","details":"pyzipper is a replacement for Python's zipfile that can read and write AES encrypted zip files. Prior to 0.4.0, a Python operator precedence bug in pyzipper/zipfile_aes.py caused the AE-2 format to never be automatically selected during encryption, causing encrypted entries to be written in AE-1 format and exposing the plaintext CRC32 checksum in the ZIP header and, for unseekable zip archives, in the datadescripter section, allowing an attacker who possesses the archive to brute-force candidate plaintexts for small or low-entropy files by comparing CRC32 values. This issue is fixed in version 0.4.0.","published":"2026-07-17T16:42:01.472Z","modified":"2026-08-12T03:51:37.111445792Z","cvss":{"score":6.2,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":{"score":0.00087,"percentile":0.00435,"asOf":"2026-08-12"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"pyzipper","fixedVersion":"0.4.0"}],"fix":{"url":"https://github.com/danifus/pyzipper/commit/93ce88e7dfd1635443197dab3fb8d477cff579ae","label":"danifus/pyzipper@93ce88e"},"references":[{"type":"WEB","url":"https://github.com/danifus/pyzipper/releases/tag/v0.4.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44722.json"},{"type":"ADVISORY","url":"https://github.com/danifus/pyzipper/security/advisories/GHSA-crqm-m339-7m2p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44722"},{"type":"FIX","url":"https://github.com/danifus/pyzipper/commit/93ce88e7dfd1635443197dab3fb8d477cff579ae"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:37.111445792Z"}}