What is CVE-2025-68645?

CVE-2025-68645 is Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion Vulnerability. The supplied enrichment data classifies it as Unclassified mapped to CWE-98 CWE-98.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Yes: CISA KEV signal present. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

Is there a public exploit?

13 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2025-68645 using CVSS 8.8, EPSS 49%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

Publicly linked actor or ransomware signals in the supplied enrichment data: White Bear (), APT 28 (), TAG-28 (), Roaming Tiger (). Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Treat as emergency remediation because CISA KEV status is present. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

CISA KEVhighpublic exploit

CVE-2025-68645

CVE-2025-68645 — Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion Vulnerability

Q: Is it in CISA KEV?

Yes. The supplied enrichment data lists CVE-2025-68645 in CISA KEV with required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

A Local File Inclusion (LFI) vulnerability exists in the Webmail Classic UI of Zimbra Collaboration (ZCS) 10.0 and 10.1 because of improper handling of user-supplied request parameters in the RestFilter servlet. An unauthenticated remote attacker can craft requests to the /h/rest endpoint to influence internal request dispatching, allowing inclusion of arbitrary files from the WebRoot directory.

Published Dec 22, 2025Updated Jun 17, 2026Sources: NVD, Synacor (CNA), CISA, FIRST EPSS, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Confirmed

CISA KEV, listed Jan 22, 2026

EPSS

49%

ahead of 99% of scored CVEs

Affects

Synacor

Zimbra Collaboration Suite (ZCS)

CVSS base

8.8

high

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

Active

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade Zimbra Collaboration Suite (ZCS) to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Federal deadline Feb 12, 2026 — passed 218 days ago

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Treat as emergency remediation because CISA KEV status is present.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Synacor	Zimbra Collaboration Suite (ZCS)	—	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

Required

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
8.8	CVSS 3.1	high	2.8	5.9	CNA

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Weakness & attack patterns

CWE-98

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-193 · PHP Remote File Inclusion

CISA KEV details

CISA lists a CVE here once it has evidence of exploitation against real targets.

CISAThat month →

Listed

Jan 22, 2026

Federal deadline

Feb 12, 2026

passed 218 days ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

Exploit entries

Exploit-DB and CTI exploit indexes

Social mentions

Posts naming this CVE. Attention, not evidence of exploitation — it spikes on disclosure and decays whether or not anything is exploited.

20 more posts on this CVEShowing 5 of 25 · Who is discussing this CVE, and how loudlyUnlock free

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /h/rest.
Prioritize edge telemetry for network-reachable Zimbra Collaboration Suite (ZCS).
Monitor for scanner or exploit-pattern traffic after 13 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Groups associated with this CVE

Groups reported in connection with this vulnerability. A reported association, not a confirmed observation of that group using it — and not scoped to any sector or campaign.

White BearAPT 28TAG-28Roaming Tiger

ip89.144.31.1837
URLhaus Feeds · Dec 7, 2025
hashaa0d3859d6633b62bccfb69017d33a8979a3be1f3f0a5a4bf6960d6c73d4112199
Computer Incident Response Center Luxembourg (CIRCL) · Oct 6, 2025
hash6f746388853178a3b4c2c91a6bd98438fb59e760caa273a8d6a4c03936498c39100
AlienVault OTX Feeds · Jan 20, 2026
hash6fd538e4a8e3493dda6f9fcdc96e814bdd14f3e2ef8aa46f0143bff34b882c1b99
Computer Incident Response Center Luxembourg (CIRCL) · Oct 3, 2025
hash23094d64721a279c0ce637584b87d6f199
SOCRadar Threat Exchange Services · Oct 7, 2025

5 more indicators on this CVEShowing 5 of 10 · Hashes, addresses and domains from a live threat exchangeUnlock free

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 8.8 (AV:N)
Jun 17, 2026 · NVD
Cve is exploited HarisAidhin/Poc_CVE-2025-68645
May 8, 2026 · SOCRadar CTI
Cve is exploited faysalferdous/CVE-2025-68645-Exploiting-Zimbra-Webmail-LFI-Vulnerability
Feb 10, 2026 · SOCRadar CTI
Added to CISA KEV catalog
Jan 22, 2026 · CISA
2025
Initial · CVE published
Dec 22, 2025 · NVD

Source activity

Readings a source repeats on a schedule, counted rather than listed.

17×SVRS was changedFeb 5, 2026 – Jun 1, 2026 · SOCRadar CTI
5×Github ReposFeb 10, 2026 – May 6, 2026 · SOCRadar CTI
4×Tweets · 1 time tweeted.Feb 7, 2026 – Mar 17, 2026 · SOCRadar CTI
2×1 time mentioned on 1 Telegram channelFeb 4, 2026 – Aug 29, 2026 · SOCRadar CTI

References

4 on the record

wiki.zimbra.com/wiki/Security_Center
Release Notes, Vendor Advisory, NIST
wiki.zimbra.com/wiki/Zimbra_Responsible_Disclosure_Policy
Product, NIST
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-68645
US Government Resource
nvd.nist.gov/vuln/detail/CVE-2025-68645
Vendor Advisory

Coverage

16 stories from the feeds we poll

11 more reports on this CVEShowing 5 of 16 · Vendor research and security press coverageUnlock free

Elsewhere on this site

Synacorevery CVE for this vendor
January 2026what else CISA listed
Unclassifiedsame class
CWE-98other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

Only the 5 indicator(s) reported for this CVE are available; no packet-level or host-forensic artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2025-68645 is Synacor Zimbra Collaboration Suite (ZCS) PHP Remote File Inclusion Vulnerability, a high vulnerability affecting Zimbra Collaboration Suite (ZCS) from Synacor. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 13 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 8.8 describes technical severity, while EPSS 49% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.