VulnerabilityPublished 19 Oct 2026Updated 30 Oct 2026

CVE-2026-86589: Apache Answer · Incorrect Implementation of Authentication Algorithm Vulnerability

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Authoritative record:CVE-2026-86589· Medium 5.4

Not known to be exploited · CVSS 5.4 Medium · fixed in 2.0.3 : update Apache Answer when convenient.

Data as of 30 Oct 2026, 21:06 UTC

CVSS 3.1 base score

5.4Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CISA-ADP	CVSS 3.1	5.4

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.
Patch: Available – fixed in 2.0.3

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

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

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: 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: 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 impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 19 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 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.

ghsa-9w3m-gv8w-f7ww

What to do

Affected software

Product	Affected	Fixed in
Apache Software FoundationApache Answer	Affected <=2.0.2	Fixed in–
Mavenorg.apache/answer`pkg:maven/org.apache/answer`Other threats	Affected <=2.0.2	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Users should upgrade Apache Answer to version 2.0.3 or later, where this vulnerability is fixed. No other mitigation or temporary workaround is indicated.

Description

Apache Answer through version 2.0.2 contains a vulnerability in its authentication algorithm due to incorrect implementation. Specifically, a flaw in the User Center login integration causes newly created external user sessions to omit their external identity. This omission allows subsequent requests to bypass central account suspension or deletion checks until the session expires or is revoked. The issue is fixed in version 2.0.3.

Impact

The vulnerability allows bypassing of central account suspension or deletion checks for external user sessions, which could lead to unauthorized access or continued access by users whose accounts should be suspended or deleted. The impact is limited to confidentiality and integrity with no reported availability impact.

Summary

CVE-2026-86589 describes a vulnerability in Apache Answer's authentication mechanism affecting versions up to 2.0.2. The flaw arises from improper handling of external user sessions in the User Center login integration, where the external identity is omitted upon session creation. This omission enables attackers to bypass central account suspension or deletion checks during the session lifetime, potentially allowing unauthorized access. The vulnerability has a CVSS 3.1 base score of 5.4 (medium severity). The issue is resolved in Apache Answer version 2.0.3.

CWE-303Incorrect Implementation of Authentication Algorithm (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Reflection Attack in Authentication Protocol (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 21:06 UTC

WeaknessesCWE-303

Technical details

References

Community reviews

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