CVE-2026-118599: Epiphany browser · A file overwrite vulnerability exists in Epiphany when installing WebExtension
Affects epiphany-browserSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 5.5 Medium.
Data as of 5 Nov 2026, 12:35 UTC
Thin evidence
One scorer or none| CNA (fedora) | CVSS 3.1 | 5.5 |
|---|
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 31 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10epiphany-browserpkg:deb/ubuntu/epiphany-browser?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSepiphany-browserpkg:deb/ubuntu/epiphany-browser?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSepiphany-browserpkg:deb/ubuntu/epiphany-browser?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSepiphany-browserpkg:deb/ubuntu/epiphany-browser?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 20.04 LTSepiphany-browserpkg:deb/ubuntu/epiphany-browser?arch=source&distro=focalOther threats | Affected
| Fixed in– |
Ubuntu 18.04 LTSepiphany-browserpkg:deb/ubuntu/epiphany-browser?arch=source&distro=bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
A file overwrite vulnerability exists in Epiphany when installing WebExtension packages from .xpi files. In 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. This is related to but separate from the ZIP-slip path traversal fixed as CVE-2026-77679 (#2922 / MR !2143). Requirements: the victim must install or open a malicious WebExtension (.xpi). Affected: Epiphany >= 47.0 (WebExtension XPI install path). Fixed: https://gitlab.gnome.org/GNOME/epiphany/-/merge_requests/2248 (commit 0cc9ab55 — only enable ZIP format support). Upstream: https://gitlab.gnome.org/GNOME/epiphany/-/work_items/2988 Reporter acknowledgment: Fernando Munoz
References
- ubuntu.com/security/CVE-2026-118599 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-118599 (opens in a new tab)
- gitlab.gnome.org/GNOME/epiphany/-/work_items/2988 (opens in a new tab)
- gitlab.gnome.org/GNOME/epiphany/-/merge_requests/2248 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-118599 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2562969 (opens in a new tab)