CVE-2026-54339: Glean: Server-Side Request Forgery (SSRF) with Full Response Disclosure via Malicious RSS Feed in /api/feeds/discover
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
Glean is a self-hosted RSS reader and personal knowledge management tool. Prior to 0.2.6, POST /api/feeds/discover passes an attacker-supplied feed_url to discover_feed(feed_url), creates a subscription through FeedService.create_subscription(), and enqueues fetch_feed_task. The background path calls fetch_feed(feed.url) and parse_feed(), which assigns each RSS item link to ParsedEntry.url. The task then passes ParsedEntry.url to fetch_and_extract_fulltext(parsed_entry.url) without network-level validation in backend/packages/rss/glean_rss/extractor.py and backend/apps/worker/glean_worker/tasks/feed_fetcher.py. A malicious feed can therefore make the server request private, loopback, link-local, or cloud-metadata resources. The fetched response is stored in Entry.content and can be retrieved through GET /api/entries/{id}, producing non-blind server-side request forgery with full response disclosure. This can bypass network perimeters, probe internal services and ports, expose internal configuration or web content, and potentially disclose cloud metadata access tokens. This issue is fixed in version 0.2.6.
Description quoted from the CVE record (assigned by GitHub_M, published 2026-09-17).
Weakness: CWE-918: Server-Side Request Forgery (SSRF)
How it can be exploited
Exploitable over the network with low attack complexity needing low privileges and no user interaction. Impact: confidentiality high, integrity none, availability none. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
CISA assessment (SSVC): CISA assesses that a public proof of concept exists. Automatable: no. Technical impact: partial.
Public exploit evidence (Exploit Observer)
Also known as: EUVD-2026-82429
VEDAS cluster: VEDAS:DIAMONDDEERHOUND
Exploit Observer links 3 pieces of public exploit code or detection modules that name this CVE or one of its aliases.
Exploit code and modules (3)
Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.
- Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-54339.rules
- Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-54339.rules
- Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-54339.rules
Vulnerability databases and vendor advisories (2)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-82429
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-54339
2 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.005
low predicted chance of attack - VEDAS
- 0.985
strong exploit evidence - On CISA KEV
- Not listed
- Detection rule
- Suricata
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| LeslieLeung glean | version < 0.2.6 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.
How to detect it
Suricata rules (network detection)
1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-54339 Glean - Server-Side Request Forgery via feeds discover feed_url. Add them to your Suricata rule set and reload.
Show the rules
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-54339 Glean - Server-Side Request Forgery via feeds discover feed_url"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/api/feeds/discover"; nocase; fast_pattern; http.request_body; content:"feed_url"; nocase; content:"://"; classtype:web-application-attack; reference:cve,CVE-2026-54339; reference:url,https://www.exploit.observer/?keyword=CVE-2026-54339&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=glean&match=exact; sid:1095204; rev:1;)
CVE-2026-54339.rules on GitHub
References
Other references
- https://github.com/LeslieLeung/glean/security/advisories/GHSA-78qf-q8fg-jcpg (x_refsource_CONFIRM)
- https://github.com/LeslieLeung/glean/commit/cdc05dd34df58d8d210e0cbed0ccc60108e4eeed (x_refsource_MISC)
- https://github.com/LeslieLeung/glean/releases/tag/v0.2.6 (x_refsource_MISC)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.