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Threats / Roundcube / CVE-2025-49113
CVE-2025-49113 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Roundcube Webmail vulnerability

Roundcube Webmail contains a deserialization vulnerability in the settings upload handler that allows authenticated users to execute arbitrary code via an unvalidated _from parameter.

Verdict

Today item — known-exploited.

An authenticated attacker can exploit improper deserialization of untrusted data in the upload.php settings action to achieve remote code execution on the Roundcube server, potentially compromising email data and server integrity.

CISA KEV Yes · 2026-02-203EPSS 0.89462 (verify live)4Exploit Weaponized · public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
10 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-02-20).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.89462 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Roundcube, Webmail. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-502 Deserialization of Untrusted Data — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established 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
I craft a malicious _from parameter containing serialized PHP objects designed to execute code when deserialized.
Business
An authenticated user account becomes a pivot point for server compromise, enabling data theft, lateral movement, and service disruption.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I send a request to program/actions/settings/upload.php with my crafted payload, bypassing validation checks.
Business
The webmail infrastructure is compromised without requiring additional exploitation steps, directly exposing all user mailboxes and credentials.
3

Lateral reach — past segmentation narrative 3

Attacker
I execute arbitrary code with the privileges of the web server process to install backdoors or exfiltrate data.
Business
Persistent unauthorized access is established, enabling ongoing surveillance of communications and compliance violations.
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)
  • EPSS probability (FIRST)
  • Weaponized exploit available (VulnCheck)
  • 10 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by mitre (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 mitreCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.