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TI-2026-83539 Aliases CVE-2026-118599GHSA-h27g-h5mg-6hm2

Hard-link handling in Epiphany lets crafted .xpi overwrite user files

Priority LOW 24CWE-59Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

GNOME Epiphany from 47.0 onward extracts WebExtension .xpi files as TAR archives without requiring a real ZIP. A crafted hard-link entry (CWE-59) can make the installer overwrite and truncate an existing user-writable file with attacker-chosen content. A local attacker must get a user to install or open a malicious .xpi file, and user interaction is required.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Description from the CNA

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00182 7th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
GNOMEEpiphany47.0 and later—No fix listedCNA
  • Epiphany VendorGNOME Affected 47.0 and later Fixed in — No fix listed CNA

Remediation

The sources list no fixed version for Epiphany.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-31 Threatist record created from CVE-2026-118599
  2. 2026-10-31 Alias added: GHSA-h27g-h5mg-6hm2
  3. 2026-11-01 Priority changed: MEDIUM → LOW
  4. 2026-11-06 CISA SSVC decision points changed

References

Other 4

  • TI-2023-23091 Gnome-maps: gnome maps is vulnerable to a code injection attack (similar to xss) via its service.json CVSS 3.1CRITICAL 9.8
  • TI-2026-41775 Glib: off-by-one error in glib/gkeyfile.c via "g_key_file_get_locale_string_list" CVSS 3.1HIGH 8.6
  • TI-2026-41772 Glib: out-of-bounds read in glib/gdatetime.c:g_date_time_get_ymd via invalid gdatetime CVSS 3.1HIGH 7.5
  • TI-2026-03716 Libsoup: libsoup: denial of service via use-after-free in http/2 server CVSS 3.1HIGH 7.5
  • TI-2024-28393 Integer overflow in GNOME G Structured File Library CVSS 3.1HIGH 8.4
  • TI-2024-24253 Integer overflow in GNOME G Structured File Library CVSS 3.1HIGH 8.4
See all 402 →

Sources

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