The UpdraftPlus: WP Backup & Migration Plugin plugin for WordPress is vulnerable to...

Description

The UpdraftPlus: WP Backup & Migration Plugin plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 1.26.4 via the UpdraftPlus_Remote_Communications_V2::wp_loaded function. This is due to insufficient validation of the remote communications message format, where signature verification can be bypassed and unchecked decryption return values collapse to a predictable all-zero encryption key. This makes it possible for unauthenticated attackers to forge arbitrary RPC commands and run them as the connected administrator, such as uploading and activating a malicious plugin, which ultimately leads to remote code execution.

Basic information

Type
unreviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Not specified
Published (advisory)
2026-06-11 09:31:55 UTC
Updated
2026-06-11 09:32:01 UTC
NVD published
2026-06-11

EPSS Score

Score Percentile
0.03% 10.88%

CVSS Scores

Base score Version Severity Vector
8.1 3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H 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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

CWEs

CWE id Name
CWE-347 Improper Verification of Cryptographic Signature

References

cvelogic Threat Intelligence