CVE-2026-29178

Lemmy: Unauthenticated SSRF via file_type query parameter injection in image endpoint

HIGH
7.7
CVSS Score
Published: March 6, 2026 at 05:56 PM UTC
Updated: June 17, 2026 at 10:29 AM UTC
1 product affected across 1 vendorLemmy Lemmy

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Severity
HIGH7.7
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

Lemmy, a link aggregator and forum for the fediverse, is vulnerable to server-side request forgery via a dependency on activitypub_federation, a framework for ActivityPub federation in Rust. Prior to version 0.19.16, the GET /api/v4/image/{filename} endpoint is vulnerable to unauthenticated SSRF through parameter injection in the file_type query parameter. An attacker can inject arbitrary query parameters into the internal request to pict-rs, including the proxy parameter which causes pict-rs to fetch arbitrary URLs. This issue has been patched in version 0.19.16.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.19.16
Affected range stops below 0.19.16, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.7HIGHGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-918

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