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Full vulnerability report · 2016
CVE-2016-3081High confidence

Apache Struts Command Injection Vulnerability

Apache · Struts

8.1HighCVSS 3.1
Recommended action
Patch now

CISA confirms exploitation in the wild and lists 2026-10-11 as the remediation due date.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 8 Oct 2026

Evidence used

  • CISA confirms exploitation in the wild.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 96.53% for the current model date.

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

  1. Confirm that the asset runs Apache Struts and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Open-source package ranges3 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 packageAffected rangeFirst fixed versionEvidence
mavenorg.apache.struts:struts2-core>= 2.3.19, <= 2.3.20.22.3.20.3GitHub advisory ↗github reviewed aggregator · 1 Nov 2023
mavenorg.apache.struts:struts2-core>= 2.3.25, <= 2.3.282.3.28.1GitHub advisory ↗github reviewed aggregator · 1 Nov 2023
mavenorg.apache.struts:struts2-core>= 2.3.21, <= 2.3.24.22.3.24.3GitHub advisory ↗github reviewed aggregator · 1 Nov 2023
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2022-3161

CISA KEV mirrored by ENISA

Apache Struts 2.3.19 to 2.3.20.2, 2.3.21 to 2.3.24.1, and 2.3.25 to 2.3.28, when Dynamic Method Invocation is enabled, allow remote attackers to execute arbitrary code via method: prefix, related to chained expressions.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 8 Oct 2026. Evidence sources: cisa_kev.
ENISA score
8.1 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch now

CISA confirms exploitation in the wild and lists 2026-10-11 as the remediation due date.

Patch available
01

What, why and how

Apache Struts contains a command injection vulnerability that could allow remote attackers to execute arbitrary code via method:prefix when Dynamic Method Invocation is enabled.

What

Apache Struts contains a command injection vulnerability that could allow remote attackers to execute arbitrary code via method:prefix when Dynamic Method Invocation is enabled.

Why

Untrusted input reaches a command interpreter without sufficient validation or separation from command syntax.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

What

Apache Struts contains a command injection vulnerability that could allow remote attackers to execute arbitrary code via method:prefix when Dynamic Method Invocation is enabled.

Why

Untrusted input reaches a command interpreter without sufficient validation or separation from command syntax.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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 exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2026-10-08.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

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 → Improper Neutralization of Special Elements used in a Command ('Command Injection') → execute code or commands in the affected security context
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-77 ↗

CWE-77: Improper Neutralization of Special Elements used in a Command ('Command Injection'). The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

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:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Common 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.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's 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.
NetworkUnauthenticatedRemote code executionCWE-77CISA KEVPublic exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2022-3161Known-exploited evidence recorded

Apache Struts 2.3.19 to 2.3.20.2, 2.3.21 to 2.3.24.1, and 2.3.25 to 2.3.28, when Dynamic Method Invocation is enabled, allow remote attackers to execute arbitrary code via method: prefix, related to chained expressions.

Official EUVD record ↗
BSI · German · WID-SEC-2026-3852Apache Struts: Mehrere Schwachstellen ermöglichen Ausführen von beliebigem Programmcode mit den Rechten des Dienstes

Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Apache Struts ausnutzen, um beliebigen Programmcode mit den Rechten des Dienstes auszuführen.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2016-002326Apache Struts2 に任意のコード実行の脆弱性

Apache Struts2 には、任意のコードを実行可能な脆弱性が存在します。 Apache Struts2 には、Dynamic Method Invocation を有効にしている場合、任意のコードを実行可能な脆弱性が存在します。 なお、本脆弱性を使用した proof-of-concept コードが公開されています。 National Vulnerability Database (NVD) では、CWE-77 として公開されています。 CWE-77: Improper Neutralization of Special Elements used in a Command (コマンドインジェクション) http://cwe.mitre.org/data/definitions/77.html

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-6984美 CISA 발표 주요 Exploit 정보공유(Update. 2026-10-08)

Apache Struts Command Injection Vulnerability

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-4627Apache Struts2 보안 업데이트 권고

원격 코드 실행 취약점(CVE-2016-3081, CVE-2016-3082) [3][4]

Official advisory ↗
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
Affected
n/a
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.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 26 Apr 2016 · Last source change 9 Oct 2026, 03:55 UTC · CWE-77 · Improper Neutralization of Special Elements used in a Command ('Command Injection')

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-01
European sourceENISA EUVD · EUVD-2022-3161
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. BlackTree coverageBlackTree article coverage changed from no BlackTree article to 1 BlackTree article.
    Before
    no BlackTree article
    After
    1 BlackTree article
    BlackTree editorial ↗
  2. Vendor guidanceAuthoritative vendor guidance changed: removed vendor advisory: oracle.com/cpuoct2016-2881722.html.
    Before
    patch: oracle.com/cpujul2016-2881720.html · patch: struts.apache.org/s2-032.html · remediation: struts.apache.org/s2-032.html · 1 more references
    After
    patch: oracle.com/cpujul2016-2881720.html · patch: struts.apache.org/s2-032.html · remediation: struts.apache.org/s2-032.html
    struts.apache.org ↗
  3. Public exploit evidencePublic exploit evidence changed from Public exploit reference to Public exploit reference.
    Before
    Public exploit reference
    After
    Public exploit reference
    exploit-db.com ↗
  4. CVSS scoreCVSS scoring authority changed from CISA ADP to NIST NVD; the displayed base score remained 8.1.
    Before
    8.1 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
    After
    8.1 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
    NIST NVD ↗
  5. ENISA known-exploited stateENISA EUVD now records this CVE in its known-exploited dataset.
    Before
    not listed in ENISA EUVD known-exploited dataset
    After
    listed in ENISA EUVD known-exploited dataset (EUVD-2022-3161)
    ENISA EUVD ↗
  6. CVSS scoreCVSS version changed from 3.0 to 3.1; the displayed base score remains 8.1.
    Before
    8.1 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
    After
    8.1 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
    CISA ADP ↗
  7. ENISA EUVD mappingEUVD-2022-3161 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2022-3161"}
    ENISA EUVD ↗
  8. CISA KEV stateCISA KEV now confirms exploitation in the wild.
    Before
    not listed in CISA KEV
    After
    listed in CISA KEV since 2026-10-08
    CISA KEV ↗
  9. Vendor guidanceAuthoritative vendor guidance changed: added patch: oracle.com/cpujul2016-2881720.html; added patch: struts.apache.org/s2-032.html; 2 further additions.
    Before
    no authoritative guidance recorded
    After
    patch: oracle.com/cpujul2016-2881720.html · patch: struts.apache.org/s2-032.html · remediation: struts.apache.org/s2-032.html · 1 more references
    struts.apache.org ↗
  10. Affected versionsThe structured affected or fixed version information changed.
    Before
    n/a · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    n/a · 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.
    CNA ↗
  11. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    struts.apache.org ↗
  12. Public exploit evidencePublic exploit evidence changed from Public exploit reference to Public exploit reference.
    Before
    Public exploit reference
    After
    Public exploit reference
    packetstormsecurity.com ↗
  13. SeveritySeverity changed from Unknown to High.
    Before
    Unknown
    After
    High
    NIST NVD ↗
  14. CVSS scoreCVSS score changed from not recorded to 8.1 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).
    Before
    not recorded
    After
    8.1 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
    NIST NVD ↗
  15. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2022-3161↗CISA KEV record↗Patch or update reference↗Patch or update reference↗CVE authority or vendor reference↗Public exploit reference↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗
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.
Free version - for non-commercial use only.CVE-2016-3081 · cve.blacktree.nl