CVE-2026-1356 | Converter for Media – Optimize images | Convert WebP & AVIF <= 6.5.1 - Unauthenticated Server-Side Request Forgery via src

The Converter for Media – Optimize images | Convert WebP & AVIF plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 6.5.1 via the PassthruLoader::load_image_source function. This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.

Published: 2026-02-12 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-1356 is rated Low Risk (21.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-1356

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-21 0.05% 0.02% -0.03%
2 2026-02-18 0.03% 0.05% +0.02%
3 2026-02-12 0.03%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-1356

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.2 2.5 [email protected]

Weakness enumeration for CVE-2026-1356

Affected software / configurations for CVE-2026-1356

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-1356

cvelogic Threat Intelligence