CVE-2017-20207: The Flickr Gallery plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including
CVE-2017-20207 is a critical-severity flaw (CVSS 9.8) affecting flickr gallery. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
The Flickr Gallery plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 1.5.2 via deserialization of untrusted input from the `pager ` parameter. This allows unauthenticated attackers to inject a PHP Object. Attackers were actively exploiting this vulnerability with the WP_Theme() class to create backdoors.
Why this priority
- Critical severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.7% (top 46%) |
| CISA exploited list | No |
| Weakness | CWE-502 |
| Published | 2025-10-18 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2017-20207?
flickr gallery: upgrade to newer than 1.5.2. Exact commands for each OS are on this page.
Is CVE-2017-20207 being exploited?
CVE-2017-20207 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2017-20207 affect?
CVE-2017-20207 affects flickr gallery. Severity is critical (CVSS 9.8). The Flickr Gallery plugin for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 1.5.2 via deserialization of untrusted input from the `pager ` parameter. This allows unauthenticated attackers to inject a PHP
How urgent is CVE-2017-20207?
Priority 53/100. Critical severity; Remotely exploitable, no login, no user action
Software pages
WordPress vulnerabilities · PHP vulnerabilities