VulnerabilityPublished 10 Oct 2025

CVE-2025-37727: Elastic Elasticsearch · Sensitive Data in Logs

Affects Elastic ElasticsearchSource CVE Database V5

Not known to be exploited · CVSS 5.7 Medium.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score

5.7Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Adjacent
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Elastic Elasticsearch	Affected 7.0.0 – 9.1.0 5 affected builds	Fixed in–

AI-suggested

To mitigate CVE-2025-37727, European organizations should implement the following specific measures: 1) Restrict access to Elasticsearch audit logs strictly to trusted administrators and secure log storage locations with encryption and access controls. 2) Limit the use of the reindex API to only necessary users and roles, employing the principle of least privilege to reduce exposure. 3) Review and sanitize any sensitive information included in reindex API requests before they are logged, potentially by configuring or customizing logging settings to exclude sensitive fields. 4) Monitor audit logs for unexpected sensitive data patterns and implement alerting for anomalous access or data leakage indicators. 5) Employ network segmentation and firewall rules to restrict access to Elasticsearch nodes and APIs, minimizing the attack surface. 6) Keep Elasticsearch versions up to date and watch for vendor patches or advisories addressing this vulnerability. 7) Conduct regular security audits and penetration testing focused on log management and API usage to identify and remediate weaknesses. These targeted actions go beyond generic advice by focusing on controlling sensitive data exposure in logs and minimizing privileges related to the vulnerable API.

Description

Insertion of sensitive information in log file in Elasticsearch can lead to loss of confidentiality under specific preconditions when auditing requests to the reindex API https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-reindex

Impact

For European organizations, the primary impact of CVE-2025-37727 is the potential unauthorized disclosure of sensitive information through Elasticsearch logs. This can compromise confidentiality of internal data, user credentials, or sensitive query parameters, which may lead to further attacks such as privilege escalation or data exfiltration. Organizations subject to strict data protection regulations like GDPR face increased compliance risks if sensitive personal data is exposed. The vulnerability does not affect data integrity or service availability directly, but the confidentiality breach could undermine trust and lead to reputational damage. Industries such as finance, healthcare, government, and telecommunications, which often use Elasticsearch for large-scale data indexing and search, are particularly vulnerable. The requirement for low privileges means that insider threats or compromised accounts with limited access could exploit this vulnerability. Additionally, the lack of user interaction needed facilitates automated exploitation once access is obtained. Overall, the vulnerability poses a moderate risk that could escalate if combined with other attack vectors.

CWE-532Insertion of Sensitive Information into Log File (opens in a new tab)
Base weaknessLikelihood of exploit: MediumOWASP Top 10 A09:2025: Security Logging & Alerting Failures (opens in a new tab)
The product writes sensitive information to a log file.
Architecture and Design · Implementation
Consider seriously the sensitivity of the information written into log files. Do not write secrets into the log files.
Distribution
Remove debug log files before deploying the application into production.
Operation
Protect log files against unauthorized read/write.
OWASP Cheat Sheets
Application Logging Vocabulary (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V7.1.1 (opens in a new tab)
V7.1.2 (opens in a new tab)
V8.3.5 (opens in a new tab)
Attack patterns
Fuzzing for application mapping (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

discuss.elastic.co/t/elasticsearch-8-18-8-8-19-5-9-0-8-9-1-5-security-update-esa-2025-18/382453 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Oct 2025, 10:18 UTC

WeaknessesCWE-532

Technical details

References

Community reviews

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