CVE-2026-54565
rhwp browser extension performs SSRF / private-network requests and leaks HWP preview data to untrusted pages
Description
rhwp is an HWP viewer and editor implemented in Rust and WebAssembly. Prior to rhwp 0.7.15 and rhwp Chrome and Firefox extension 0.2.4, the browser extensions use an all-URLs host permission to detect HWP and HWPX links on visited pages, but the service workers do not validate message senders, URL schemes, or destination addresses before privileged fetches. The affected paths are rhwp-chrome/manifest.json, rhwp-chrome/content-script.js, rhwp-chrome/sw/message-router.js, rhwp-chrome/sw/thumbnail-extractor.js, rhwp-firefox/manifest.json, rhwp-firefox/content-script.js, rhwp-firefox/sw/message-router.js, and rhwp-firefox/sw/thumbnail-extractor.js. An untrusted page can make the fetch-file and extract-thumbnail handlers request localhost or private-network resources. When a target HWP or HWPX file contains an extractable PrvImage, the extension returns the preview as a data URI in page-readable DOM, allowing page script to read it. The flaw also permits internal-resource existence and port probing and extension presence or version fingerprinting. Exploitation requires a user to visit an untrusted page while the extension is enabled, and preview disclosure is limited to an extractable PrvImage. This issue is fixed in rhwp 0.7.15 and rhwp Chrome and Firefox extension 0.2.4.
INFO
Published Date :
Sept. 17, 2026, 9:17 p.m.
Last Modified :
Sept. 24, 2026, 9:25 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-54565
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update rhwp to version 0.7.15 or later.
- Update rhwp browser extensions to version 0.2.4 or later.
- Validate message sender, URL schemes, and addresses.
- Restrict host permissions where possible.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54565.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54565 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54565
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54565 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54565 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 21, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-54565', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-21T21:13:29.847940Z'} -
New CVE Received by [email protected]
Sep. 17, 2026
Action Type Old Value New Value Added Description rhwp is an HWP viewer and editor implemented in Rust and WebAssembly. Prior to rhwp 0.7.15 and rhwp Chrome and Firefox extension 0.2.4, the browser extensions use an all-URLs host permission to detect HWP and HWPX links on visited pages, but the service workers do not validate message senders, URL schemes, or destination addresses before privileged fetches. The affected paths are rhwp-chrome/manifest.json, rhwp-chrome/content-script.js, rhwp-chrome/sw/message-router.js, rhwp-chrome/sw/thumbnail-extractor.js, rhwp-firefox/manifest.json, rhwp-firefox/content-script.js, rhwp-firefox/sw/message-router.js, and rhwp-firefox/sw/thumbnail-extractor.js. An untrusted page can make the fetch-file and extract-thumbnail handlers request localhost or private-network resources. When a target HWP or HWPX file contains an extractable PrvImage, the extension returns the preview as a data URI in page-readable DOM, allowing page script to read it. The flaw also permits internal-resource existence and port probing and extension presence or version fingerprinting. Exploitation requires a user to visit an untrusted page while the extension is enabled, and preview disclosure is limited to an extractable PrvImage. This issue is fixed in rhwp 0.7.15 and rhwp Chrome and Firefox extension 0.2.4. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N Added CWE CWE-200 Added CWE CWE-918 Added CWE CWE-359 Added CWE CWE-1385 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/54xxx/CVE-2026-54565.json">CVE-2026-54565</a> Added Reference https://github.com/edwardkim/rhwp/commit/e07b76ba79f42078c6cdf1045b58f894ec55bdf9 Added Reference https://github.com/edwardkim/rhwp/releases/tag/v0.7.15 Added Reference https://github.com/edwardkim/rhwp/security/advisories/GHSA-j972-m9fh-g22m