CVE-2026-16267

HIGHPre-NVD 8.18.1—
EchelonGraph scoreHIGH confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-08-08. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
8.1
EG Score
8.1(high)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity81% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

August 8, 2026

Last Modified

August 11, 2026

Advisory Details (1)

Auto-updated Aug 11, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

Newsletters < 4.16 – Unauthenticated PHP Object Injection via Date Form Field | CVE 2026-16267 | Plugin Vulnerabilities

https://wpscan.com/vulnerability/b51c11d6-5bfa-4b2c-b348-cda19889deee/

Vendor Advisories for CVE-2026-16267(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 26× in last 7d / 48× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 19:56 UTCGHSA enrichment
  3. 2026-08-20 07:19 UTCGHSA enrichment
  4. 2026-08-19 18:46 UTCEG score recompute
  5. 2026-08-19 18:46 UTCGHSA enrichment
  6. 2026-08-19 17:03 UTCEPSS rescore
  7. 2026-08-19 04:13 UTCGHSA enrichment
  8. 2026-08-18 15:40 UTCEG score recompute
  9. 2026-08-18 15:39 UTCGHSA enrichment
  10. 2026-08-18 13:48 UTCEPSS rescore
  11. 2026-08-18 02:53 UTCGHSA enrichment
  12. 2026-08-17 14:20 UTCEG score recompute
  13. 2026-08-17 14:20 UTCGHSA enrichment
  14. 2026-08-17 13:47 UTCEPSS rescore
  15. 2026-08-17 01:48 UTCEG score recompute
  16. 2026-08-17 01:48 UTCGHSA enrichment
  17. 2026-08-16 14:56 UTCEPSS rescore
  18. 2026-08-16 13:15 UTCEG score recompute
  19. 2026-08-16 13:15 UTCGHSA enrichment
  20. 2026-08-16 02:14 UTCEPSS rescore
  21. 2026-08-16 00:42 UTCGHSA enrichment
  22. 2026-08-15 12:09 UTCEG score recompute
  23. 2026-08-15 12:09 UTCGHSA enrichment
  24. 2026-08-15 01:30 UTCEPSS rescore
  25. 2026-08-14 23:36 UTCGHSA enrichment
Show 23 more
  1. 2026-08-14 11:04 UTCGHSA enrichment
  2. 2026-08-13 22:31 UTCEG score recompute
  3. 2026-08-13 22:31 UTCGHSA enrichment
  4. 2026-08-13 22:00 UTCEPSS rescore
  5. 2026-08-13 09:58 UTCGHSA enrichment
  6. 2026-08-12 21:26 UTCEG score recompute
  7. 2026-08-12 21:26 UTCGHSA enrichment
  8. 2026-08-12 13:50 UTCEPSS rescore
  9. 2026-08-12 08:53 UTCEG score recompute
  10. 2026-08-12 08:53 UTCGHSA enrichment
  11. 2026-08-11 20:20 UTCGHSA enrichment
  12. 2026-08-11 19:51 UTCEG score recompute▲ 8.10
  13. 2026-08-11 19:51 UTCGHSA enrichment
  14. 2026-08-11 19:50 UTCMITRE cvelistV5CVSS v3 → 8.1 · severity → HIGH
  15. 2026-08-11 13:49 UTCEG score recompute
  16. 2026-08-11 13:49 UTCGHSA enrichment
  17. 2026-08-11 13:42 UTCEPSS rescore
  18. 2026-08-11 00:00 UTCEPSS rescore
  19. 2026-08-09 13:46 UTCEPSS rescore
  20. 2026-08-08 16:37 UTCEPSS rescore
  21. 2026-08-08 07:19 UTCNVD update
  22. 2026-08-08 06:22 UTCEG score recompute
  23. 2026-08-08 06:22 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-16267?
CVE-2026-16267 is a high vulnerability published on August 8, 2026. 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.
When was CVE-2026-16267 disclosed?
CVE-2026-16267 was first published in the National Vulnerability Database on August 8, 2026, with the most recent update on August 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16267 actively exploited?
CVE-2026-16267 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 81.0% of all scored CVEs.
What is the CVSS score of CVE-2026-16267?
CVE-2026-16267 has a CVSS v3.1 base score of 8.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-16267?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-16267, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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