VulnerabilityPublished 21 Feb 2026Updated 16 Mar 2026

CVE-2026-2861: Foswiki · Information Disclosure

Affects FoswikiSource CVE Database V5

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Public exploit available · CVSS 6.9 Medium.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 29 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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
Foswiki	Affected 2.1.0 – 2.1.10 11 affected builds	Fixed in–

AI-suggested

To mitigate CVE-2026-2861, organizations should promptly upgrade all Foswiki installations to version 2.1.11 or later, which contains the official patch for this vulnerability. Prior to upgrading, administrators should review and apply the patches identified by commit hashes 31aeecb58b64 and d8ed86b10e46 if immediate upgrade is not feasible. Additionally, organizations should restrict external access to Foswiki instances by implementing network-level controls such as firewalls or VPNs to limit exposure to trusted users only. Monitoring web server logs for unusual access patterns targeting the Changes/Viewfile/Oops component can help detect exploitation attempts. Employing web application firewalls (WAFs) with custom rules to block suspicious requests related to this component may provide temporary protection. Regularly auditing and minimizing sensitive data stored in Foswiki can reduce potential impact. Finally, organizations should maintain an incident response plan to address any suspected data breaches resulting from this vulnerability.

Description

A vulnerability was detected in Foswiki up to 2.1.10. The affected element is an unknown function of the component Changes/Viewfile/Oops. The manipulation results in information disclosure. It is possible to launch the attack remotely. The exploit is now public and may be used. Upgrading to version 2.1.11 is sufficient to fix this issue. The patch is identified as 31aeecb58b64/d8ed86b10e46. Upgrading the affected component is recommended.

Impact

The primary impact of CVE-2026-2861 is unauthorized information disclosure, which can compromise the confidentiality of sensitive organizational data managed within Foswiki environments. This may include internal documentation, project details, or other proprietary information, potentially leading to competitive disadvantage, reputational damage, or aiding further attacks such as social engineering or targeted intrusions. Since the vulnerability does not affect integrity or availability, it does not directly disrupt operations or data accuracy. However, the ease of remote exploitation without authentication increases the risk profile, especially for organizations exposing Foswiki instances to the internet. The availability of a public exploit further elevates the threat, potentially enabling widespread scanning and exploitation attempts. Organizations relying on Foswiki for collaboration and knowledge management should consider the risk of data leakage significant, particularly if sensitive or regulated information is stored within the platform.

References

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