{"id":"CVE-2026-118599","published":"2026-10-31T10:16:38.060","lastModified":"2026-10-31T10:16:38.060","description":"A file overwrite vulnerability exists in Epiphany when installing WebExtension packages from .xpi files.\n\nIn src/webextension/ephy-web-extension-manager.c, decompress_xpi_thread() used libarchive with archive_read_support_format_all() (and filters), so the installer did not require a real ZIP. A TAR file named *.xpi was extracted. TAR supports hard-link entry types; with Epiphany's archive_write_disk options (including ARCHIVE_EXTRACT_PERM), a crafted hard-link target can cause an attacker-chosen existing user-writable file to be truncated and overwritten with attacker-controlled content and mode bits, without a dedicated warning dialog, when the user installs or opens the crafted .xpi.\n\nThis is related to but separate from the ZIP-slip path traversal fixed as CVE-2026-77679 (#2922 / MR !2143).\n\nRequirements: the victim must install or open a malicious WebExtension (.xpi).\n\nAffected: Epiphany >= 47.0 (WebExtension XPI install path).\nFixed: https://gitlab.gnome.org/GNOME/epiphany/-/merge_requests/2248 (commit 0cc9ab55 — only enable ZIP format support).\nUpstream: https://gitlab.gnome.org/GNOME/epiphany/-/work_items/2988\nReporter acknowledgment: Fernando Munoz","cvssScore":5.5,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","cwes":["CWE-59"],"vendors":[],"products":[],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-118599","tags":[]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2562969","tags":[]},{"url":"https://gitlab.gnome.org/GNOME/epiphany/-/merge_requests/2248","tags":[]},{"url":"https://gitlab.gnome.org/GNOME/epiphany/-/work_items/2988","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}