CVE-2026-1357 — WPvivid — Backup, Migration & Staging

What is CVE-2026-1357?

The Migration, Backup, Staging – WPvivid Backup & Migration plugin for WordPress is vulnerable to Unauthenticated Arbitrary File Upload in versions up to and including 0.9.123. This is due to improper error handling in the RSA decryption process combined with a lack of path sanitization when writing uploaded files. When the plugin fails to decrypt a session key using openssl_private_decrypt(), it does not terminate execution and instead passes the boolean false value to the phpseclib library's AES cipher initialization. The library treats this false value as a string of null bytes, allowing an attacker to encrypt a malicious payload using a predictable null-byte key. Additionally, the plugin accepts filenames from the decrypted payload without sanitization, enabling directory traversal to escape the protected backup directory. This makes it possible for unauthenticated attackers to upload arbitrary PHP files to publicly accessible directories and achieve Remote Code Execution via the wpvivid_action=send_to_site parameter.

The record classifies CVE-2026-1357 under weakness class CWE-434. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 260 days ago.

Severity and exploitation probability

CVSS v3.1 base score: 9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (FIRST): 35.1% probability of exploitation in the next 30 days, higher than 98.4% of all scored CVEs
CISA KEV: Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority: 10/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published: 2026-02-11, last modified 2026-04-08

Is CVE-2026-1357 being exploited?

Weaponised exploit code for CVE-2026-1357 is publicly available. 10 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (http/cves/2026/CVE-2026-1357.yaml). It currently carries a trending score of 40 in the Threadlinqs vulnerability feed.

halilkirazkaya/CVE-2026-1357 (github)
LucasM0ntes/POC-CVE-2026-1357 (github)
cybertechajju/CVE-2026-1357-POC (github)
itsismarcos/Exploit-CVE-2026-1357 (github)
sahmsec/CVE-2026-1357 (github)
rootdirective-sec/CVE-2026-1357-Lab (github)
CVEs-Labs/CVE-2026-1357 (github)
Nxploited/CVE-2026-1357 (github)

Affected products and versions

wpvividplugins: WPvivid — Backup, Migration & Staging

How to fix CVE-2026-1357

No vendor patch reference has been recorded for CVE-2026-1357 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-1357

2 tracked threats in the Threadlinqs corpus reference CVE-2026-1357, either in the campaign’s CVE list or as an indicator on the campaign record.

Australia (ACSC) Warns of Global Campaign Exploiting Vulnerable CMS Platforms to Deploy Webshells — CRITICAL · 2026-07-11
PCPJack Worm — Cloud Credential Theft Framework Evicting TeamPCP Infections (CVE-2025-29927, CVE-2025-55182, CVE-2026-1357, CVE-2025-9501, CVE-2025-48703) — CRITICAL · 2026-05-07

Sources

Enriched from CVE.org, FIRST EPSS, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on 2026-10-10.

Other references

Showing 5 of 8 recorded references.

CVE-2026-1357 — wpvividplugins WPvivid — Backup, Migration & Staging