Evidence used
- CISA confirms exploitation in the wild.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 98.90% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2025
CVE-2025-49113High confidence
RoundCube Webmail Deserialization of Untrusted Data Vulnerability
Roundcube · Webmail
9.9CriticalCVSS 3.1
Patch now
Patch availableCISA confirms exploitation in the wild and lists 2026-03-13 as the remediation due date.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs Roundcube Webmail and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
5 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | roundcube | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.6.11+dfsg-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | roundcube | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.6.5+dfsg-1+deb12u5 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | roundcube | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.6.11+dfsg-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | roundcube | Vendor fix publishedDebian records a fixed source-package version for this release. | 1.6.11+dfsg-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | roundcube | Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree. | 1.6.6+dfsg-2ubuntu0.1 | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
Open-source package ranges2 source-attributed ranges
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| composerroundcube/roundcubemail | < 1.5.10 | 1.5.10 | GitHub advisory ↗github reviewed aggregator · 20 Feb 2026 |
| composerroundcube/roundcubemail | >= 1.6.0, < 1.6.11 | 1.6.11 | GitHub advisory ↗github reviewed aggregator · 20 Feb 2026 |
CISA confirms exploitation in the wild and lists 2026-03-13 as the remediation due date.
Patch available01
What, why and how
RoundCube Webmail contains a deserialization of untrusted data vulnerability that allows remote code execution by authenticated users because the _from parameter in a URL is not validated in program/actions/settings/upload.php.
What
RoundCube Webmail contains a deserialization of untrusted data vulnerability that allows remote code execution by authenticated users because the _from parameter in a URL is not validated in program/actions/settings/upload.php.
Why
Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.
What
RoundCube Webmail contains a deserialization of untrusted data vulnerability that allows remote code execution by authenticated users because the _from parameter in a URL is not validated in program/actions/settings/upload.php.
Why
Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation Confirmed in the wild
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2026-02-20.
Public PoC / exploit material Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
- Likely attack path
- a network path → Deserialization of Untrusted Data → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-502 ↗
CWE-502: Deserialization of Untrusted Data. The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Action
- Apply the fixed release for the affected product branch as recorded by Canadian Centre for Cyber Security. Validate the exact product and build in the linked advisory before deployment.
- Workaround
- A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04
Evidence and provenance
Published 2 Jun 2025 · Last source change 21 Feb 2026, 04:56 UTC · CWE-502 · Deserialization of Untrusted Data
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2025-16605
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- Affected versionsThe structured affected or fixed version information changed.Canadian Centre for Cyber Security ↗
- Before
- Webmail: < 1.5.10, 1.6.0 < 1.6.11 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- After
- Webmail: < 1.5.10, 1.6.0 < 1.6.11 · Fixed: The Cyber Centre strongly recommends that organizations update to Roundcube Webmail versions 1.5.10+ or 1.6.11+ Footnote 2 , which would mitigate issues reported by both CVEs mentioned here (CVE-2024-42009 and CVE-2025-49113). The Cyber Centre recommends that organizations: Assess the installation of Roundcube Webmail. Apply updates to Roundcube Webmail without delay. Monitor affected systems for signs of exploitation. Monitor for brute-force attempts and if possible, implement rate limitation techniques. In addition, the Cyber Centre strongly recommends that organizations review and implement the Cyber Centre's Top 10 IT Security Actions Footnote 6 with an emphasis on the following strategies: If activity matching the content of this alert is discovered, recipients are encouraged to report via the My Cyber Portal , or email contact@cyber.gc.ca .
- Vendor guidanceAuthoritative vendor guidance changed: added remediation: roundcube.net/security-updates-1.6.11-and-1.5.10; removed remediation: cyber.gc.ca/vulnerability-impacting-roundcube-webmail-cve-2025-49113.cve@mitre.org ↗
- Before
- mitigation: vicarius.io/cve-2025-49113-roundcube-mitigation-script · mitigation: vicarius.io/cve-2025-49113-roundcube-vulnerability-detection · patch: github.com/0376f69e958a8fef7f6f09e352c541b4e7729c4d · 4 more references
- After
- mitigation: vicarius.io/cve-2025-49113-roundcube-mitigation-script · mitigation: vicarius.io/cve-2025-49113-roundcube-vulnerability-detection · patch: github.com/0376f69e958a8fef7f6f09e352c541b4e7729c4d · 4 more references
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- Webmail: < 1.5.10, 1.6.0 < 1.6.11 · Fixed: The Cyber Centre strongly recommends that organizations update to Roundcube Webmail versions 1.5.10+ or 1.6.11+ Footnote 2 , which would mitigate issues reported by both CVEs mentioned here (CVE-2024-42009 and CVE-2025-49113). The Cyber Centre recommends that organizations: Assess the installation of Roundcube Webmail. Apply updates to Roundcube Webmail without delay. Monitor affected systems for signs of exploitation. Monitor for brute-force attempts and if possible, implement rate limitation techniques. In addition, the Cyber Centre strongly recommends that organizations review and implement the Cyber Centre's Top 10 IT Security Actions Footnote 6 with an emphasis on the following strategies: If activity matching the content of this alert is discovered, recipients are encouraged to report via the My Cyber Portal , or email contact@cyber.gc.ca .
- After
- Webmail: < 1.5.10, 1.6.0 < 1.6.11 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- < 1.5.10; 1.6.0 < 1.6.11 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- After
- Webmail: < 1.5.10, 1.6.0 < 1.6.11 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
CVE published
Added to CISA KEV
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2025-16605↗Canadian Centre for Cyber Security remediation guidance↗CISA KEV record↗CVE authority or vendor reference↗Patch or update reference↗Patch or update reference↗Patch or update reference↗Public exploit reference↗Public exploit reference↗Official CVE record (CNA and ADP data)↗
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.