What is CVE-2026-44963?

CVE-2026-44963 is A vulnerability allowing remote code execution (RCE) on the Backup Server by an authenticated domain user. The supplied enrichment data classifies it as Deserialization mapped to CWE-502 Deserialization of Untrusted Data.

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?

Exploitation is reported, but no independent confirmation is available in the sources we have. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-44963 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

2 public PoC repositories reported; 1 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, EDR process telemetry, host service logs 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-2026-44963 using CVSS 9.4, EPSS 2%, 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?

No public threat actor linkage is confirmed from current sources. 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. Prioritize based on EPSS, PoC availability, and external exposure. 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.

criticalDeserializationpublic exploit

CVE-2026-44963

CVE-2026-44963 — A vulnerability allowing remote code execution (RCE) on the Backup Server by an authenticated domain user

A vulnerability allowing remote code execution (RCE) on the Backup Server by an authenticated domain user.

Published Jun 9, 2026Updated Jul 23, 2026Sources: NVD, Veeam (CNA), SOCRadar CTI

Triage

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

Exploitation

Reported

not confirmed by CISA

EPSS

ahead of 82% of scored CVEs

Affects

Veeam

Backup and Replication

CVSS base

9.4

critical

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

None

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 Backup and Replication to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

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.
Prioritize based on EPSS, PoC availability, and external exposure.
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
Veeam	Backup and Replication	0 to < 12.3.2	Vulnerable

Attack characteristics

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

Scope

Attack Complexity

Low

Attack Vector

Network

Privileges Req

Low

User Interaction

None

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
9.4	CVSS 4.0	critical	—	—	Veeam (CNA)

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-502 · Deserialization of Untrusted Data

Modify Application Data
Unexpected State
DoS: Resource Consumption (CPU)
Varies by Context

Mitigation: If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.

Weakness & attack patterns

CWE-502Deserialization of Untrusted Data

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

CAPEC-586 · Object Injection

Public exploit

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

Repositories

1 of the 2 sampled are weaponized

Social mentions

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

35 more posts on this CVEShowing 5 of 40 · 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.

Prioritize edge telemetry for network-reachable Backup and Replication.
Monitor for scanner or exploit-pattern traffic after 2 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPSEDR process telemetryhost service logs

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 9.4 (AV:N)
Jul 23, 2026 · NVD
Initial · CVE published
Jun 9, 2026 · NVD

Source activity

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

23×SvrsJun 10, 2026 – Aug 28, 2026 · SOCRadar CTI
13×TweetsJun 10, 2026 – Aug 21, 2026 · SOCRadar CTI
2×Github ReposJun 10, 2026 – Jun 18, 2026 · SOCRadar CTI
1×CVE appeared in the Cve Trends.Jun 10, 2026 · SOCRadar CTI
1×1 time mentioned on 1 Telegram channelJun 10, 2026 · SOCRadar CTI

References

1 on the record

www.veeam.com/kb4869
Vendor Advisory, NIST

Coverage

17 stories from the feeds we poll

12 more reports on this CVEShowing 5 of 17 · Vendor research and security press coverageUnlock free

Elsewhere on this site

Veeamevery CVE for this vendor
Deserializationsame class
CWE-502other 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.

No confirmed IOCs, IP addresses, domains, file hashes, or malware 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-2026-44963 is A vulnerability allowing remote code execution (RCE) on the Backup Server by an authenticated domain user, a critical vulnerability affecting Backup and Replication from Veeam. The current evidence does not list it in CISA KEV, and the exploit status is: Exploitation is reported, but no independent confirmation is available in the sources we have. Public exploit evidence is: 2 public PoC repositories reported; 1 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 9.4 describes technical severity, while EPSS 2% 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.