Glean: Server-Side Request Forgery (SSRF) with Full Response Disclosure via Malicious RSS Feed in /api/feeds/discover (CVE-2026-54339) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-54339

Glean: Server-Side Request Forgery (SSRF) with Full Response Disclosure via Malicious RSS Feed in /api/feeds/discover

Answer in brief

CVE-2026-54339 records a Unknown severity vulnerability in Glean: Server-Side Request Forgery (SSRF) with Full Response Disclosure via Malicious RSS Feed in /api/feeds/discover. The current sources do not mark it as known exploited. The current feed maps LeslieLeung/glean (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps LeslieLeung/glean (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
LeslieLeung/gleangeneric	< 0.2.6	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for LeslieLeung/glean.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.