🛡️ CVE-2026-61520

🟠 CVSS 7.7 — High ✅ No Known Exploit CWE-918 NVD
7.7
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Simple Machines Forum 2.1 prior to commit 4bf35cf and 3.0 prior to commit b4d23df contains a server-side request forgery vulnerability in the image proxy that allows authenticated attackers to trigger internal HTTP requests by embedding attacker-controlled URLs in BBCode image tags, which the proxy fetches without validating resolved destination IPs against private address ranges, loopback, or link-local addresses. Attackers can leverage SMF's automatic HMAC signature generation for any embedded image URL to obtain valid signed proxy requests targeting internal services such as cloud instance metadata endpoints, internal web applications, and container network services.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity none, availability none.

Weakness class

CVE-2026-61520 is classified as CWE-918: Server-Side Request Forgery (SSRF). The server fetches a URL supplied by the caller, which can be pointed at internal systems it alone can reach.

Affected software

CVE-2026-61520 is recorded against 1 package.

  • unknown

Timeline and source

Published on 14 July 2026 and last revised on 15 July 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

github.com
github.com
www.vulncheck.com

Details

Severity HIGH
CVSS Score 7.7
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
CWE CWE-918
Public Exploit ✅ No
Source NVD
Published 2026-07-14
Updated 2026-08-11
Modified 2026-07-15
Fix URL N/A

Affected Packages

Software From version Fixed in
unknown — —

Similar Threats

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