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Threats / Meta / CVE-2025-55182
CVE-2025-55182 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-06

Meta React Server Components vulnerability

Meta React Server Components contains an unauthenticated remote code execution vulnerability in payload decoding for React Server Function endpoints. The flaw is actively exploited in the wild and associated with ransomware campaigns.

Verdict

Today item, not a backlog item.

Unauthenticated attackers can execute arbitrary code on affected React Server Components instances by sending malicious payloads to React Server Function endpoints. Active exploitation and ransomware deployment pose immediate risk to production environments.

CISA KEV Yes · 2025-12-053Ransomware use Flagged3EPSS 0.84489 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-12-05), flagged for known ransomware use.
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.84489 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
FIRST EPSS ↗High
Severity / affected
Affected: Meta, React Server Components. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No threat-actor attribution is established from the public feed for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
Craft and send a malicious payload to a React Server Function endpoint, exploiting the decoding flaw to achieve code execution without authentication.
Business
Attacker gains full system compromise, enabling data theft, service disruption, and deployment of ransomware to encrypt critical business assets.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
Execute commands within the compromised application context to establish persistence, escalate privileges, and move laterally across the infrastructure.
Business
Extended dwell time increases exposure window, allowing attackers to exfiltrate sensitive data and encrypt backups before demanding ransom.
3

Lateral reach — past segmentation narrative 3

Attacker
Deploy ransomware payloads across connected systems and encrypt business-critical data to maximize financial leverage.
Business
Operations halt, revenue stops, and organization faces extortion demands while reputational damage and regulatory penalties accumulate.
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • Ransomware-use flag (CISA)
  • EPSS probability (FIRST)
  • Catalogued by Meta (CNA)

    • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
    • Disclosure & credit2
    Catalogued by MetaCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.