8.1

CVE-2026-16267: Newsletters < 4.16 - Unauthenticated PHP Object Injection via Date Form Field

Deferred
Published 08-08-2026Last modified 11-08-2026

Vulnerability summary

CVE-2026-16267 is a high (CVSS 8.1) Deserialization of Untrusted Data vulnerability in unknown newsletters. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 38.4% of scored vulnerabilities. 1 public exploit is recorded. Fixed in 4.16.

Overall risk
42/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.45%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1reference

Timeline

  1. 08-08-2026
    PublishedVulnerability first disclosed.
  2. 11-08-2026
    Last modifiedVulnerability information updated.

Description

The Newsletters WordPress plugin before 4.16 does not restrict the classes allowed when unserialising a value taken from a public form submission, allowing unauthenticated attackers to inject arbitrary PHP objects.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.45%

Chance of exploitation in the next 30 days

Percentile

38%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.45% on 24-09-2026

24-09-202624-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (wpscan.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Unknown1 product
Wordpress1 product
  • newsletters-lite≤ 4.15 (fixed in 4.16)

2 vendors · 2 products

References

2 links