CVE-2025-42999 — SAP NetWeaver Deserialization Vulnerability

Triage

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

CISA SSVC assessment CISA

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

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

CISA required action CISA

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

US federal deadline: Jun 5, 2025 — passed 497 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

1. Identify exposed assets running the affected vendor/product/version combinations (SAP SE Netweaver, SAP SE SAP NetWeaver (Visual Composer development server)).
2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
4. EPSS ahead of 96% of scored CVEs: prioritize it in the patch queue.
5. Search available logs for exploit probes matching the vulnerability class (insecure deserialization), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Attack characteristics

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

Every base score collected

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

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-502 · Deserialization of Untrusted Data

Other CVEs with this weakness →

CISA KEV details CISA

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

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 reference date.

EPSS over time FIRST

Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 12.74%

Detection

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

• Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
• Monitor serialized objects in requests and unexpected processes spawned by the runtime.
• Hunt retroactively in logs from before May 15, 2025 (KEV listing): exploitation may have started earlier.

Timeline

What happened to this CVE, newest first.

• 2026
• Affected products added · sap se/sap netweaver (visual composer development server)
  Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
• SSVC assessment updated
  Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
• Record published
  Oct 13, 2026
• Affected products added · sap/netweaver
  Oct 13, 2026 · NIST National Vulnerability Database
• CVSS changed · 9.1
  Oct 13, 2026 · NIST National Vulnerability Database
• Source status changed · → Analyzed
  Oct 13, 2026 · NIST National Vulnerability Database
• Added to CISA KEV (detected)
  Oct 13, 2026 · CISA Known Exploited Vulnerabilities
• Record created in this database
  Oct 13, 2026 · CISA Known Exploited Vulnerabilities
• 2025
• Added to CISA KEV catalog
  May 14, 2025 · CISA
• CVE published
  May 12, 2025 · sap

Source activity

Repeated readings are counted rather than listed.

• 2× References added · Oct 13, 2026 – Oct 13, 2026
• 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

7 on the record

• url.sap/sapsecuritypatchday
  Vendor Advisory, NIST National Vulnerability Database
• www.cisa.gov/known-exploited-vulnerabilities-catalog
  US Government Resource, NIST National Vulnerability Database
• me.sap.com/notes/3604119
  Permissions Required, NIST National Vulnerability Database
• github.com/advisories/GHSA-rgq9-rg7j-xm4x
  GitHub Security Advisories
• onapsis.com/blog/active-exploitation-of-sap-vulnerability-cve-2025-31324
  GitHub Security Advisories
• nvd.nist.gov/vuln/detail/CVE-2025-42999
  GitHub Security Advisories
• onapsis.com/blog/active-exploitation-of-sap-vulnerability-cve-2025-31324/
  Exploit, Third Party Advisory, NIST National Vulnerability Database

Elsewhere on this site

Related CVEs (same products)

• Medium CVE-2026-23685 Insecure Deserialization vulnerability in SAP NetWeaver (JMS service) Feb 10, 2026
• Critical CVE-2025-31324 SAP NetWeaver Unrestricted File Upload Vulnerability KEV Apr 24, 2025
• High CVE-2021-38163 SAP NetWeaver Unrestricted File Upload Vulnerability KEV Sep 14, 2021

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 fixed version, patch or mitigation documented.
• 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 record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-42999 is "SAP NetWeaver Deserialization Vulnerability", rated Critical. It affects Netweaver (SAP SE); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.1 describes technical severity. EPSS 12.74% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.

Sign in or create an account to comment and suggest corrections.