Vulnerability in GNOME Yelp
CVE-2026-13601
A flaw was found in Yelp due to an overly permissive Content Security Policy (CSP) implementation provided by yelp-xsl. A malicious Flatpak application can open crafted help content through the OpenURI portal. By embedding an untrusted CSS stylesheet within a structured SVG document, attacker-controlled content can bypass Flatpak's intended sandbox isolation, allowing Yelp to evaluate local XML inclusions and disclose arbitrary user-readable host files through remote CSS resource requests. This may result in the unauthorized disclosure of sensitive information.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.002 (6.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 6.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- GNOME Yelp
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8 — versions 2:3.28.1-3.el8_10.2
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support — versions 2:3.28.1-3.el8_4.2
- Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On — versions 2:3.28.1-3.el8_4.2
- Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support — versions 2:3.28.1-3.el8_6.2
- Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On — versions 2:3.28.1-3.el8_6.2
- Red Hat Enterprise Linux 8.8 Telecommunications Update Service — versions 2:3.28.1-3.el8_8.2
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-13601 (vdb-entry, Vendor Advisory)
- blogs.gnome.org/mcatanzaro/2026/05/11/flatpak-sandbox-escape-via-yelp/ (Third Party Advisory)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Issue Tracking, Vendor Advisory)
- gitlab.gnome.org/GNOME/yelp/-/commit/c8c8244c8a812860782d635890c9b6c43ecc2639 (Patch)
- gitlab.gnome.org/GNOME/yelp/-/work_items/238 (Third Party Advisory, Mitigation, Issue Tracking)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Vendor Advisory)
- access.redhat.com/errata/RHSA-2026:47177 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:47178 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:54540 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:54539 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-13601?
- CVE-2026-13601 is a high-severity vulnerability in GNOME Yelp, classified under Protection Mechanism Failure. CVSS score: 7.1/10. Published 2026-06-29.
- How severe is CVE-2026-13601?
- High severity. CVSS v3 base score is 7.1 out of 10.