VulnerabilityPublished 3 Jan 2024Updated 3 Jun 2025

CVE-2023-45559

Source CVE Database V5

Not known to be exploited · CVSS 8.2 High.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

8.2High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: 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 3 Jan 2024
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
GitHubsyz913/Line`pkg:github/syz913/Line`Other threats	Affected =13.6.1	Fixed in–

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AI-suggested

To mitigate CVE-2023-45559 effectively, organizations should first identify if they are using Tamaki_hamanoki Line version 13.6.1 or related vulnerable versions. Immediate steps include: 1) Restricting and rotating channel access tokens to invalidate potentially leaked credentials. 2) Implementing strict access controls and monitoring for unusual notification activity to detect unauthorized message sending. 3) Employing network-level protections such as firewall rules and intrusion detection systems to limit exposure of the messaging platform's API endpoints. 4) Enhancing logging and alerting mechanisms to capture anomalous usage patterns related to notification sending. 5) Engaging with the vendor or community to obtain patches or updates addressing the vulnerability, and applying them promptly once available. 6) Educating users and administrators about phishing and social engineering risks stemming from unauthorized notifications. 7) Considering additional authentication layers or token scope restrictions to minimize the impact of token leakage. These measures go beyond generic advice by focusing on token management, monitoring, and layered defenses tailored to the vulnerability's exploitation vector.

Description

An issue in Tamaki_hamanoki Line v.13.6.1 allows attackers to send crafted notifications via leakage of the channel access token.

Impact

For European organizations, the impact of CVE-2023-45559 can be substantial, particularly for those using the affected messaging platform for business communications, customer engagement, or internal notifications. Unauthorized crafted notifications can lead to misinformation dissemination, phishing attacks, or social engineering campaigns targeting employees or customers. This can result in data breaches, financial fraud, reputational damage, and erosion of trust. Confidentiality is highly at risk due to token leakage, potentially exposing sensitive communication channels or user data. Although the integrity impact is low, the ability to send unauthorized messages can indirectly affect operational decisions and security postures. The lack of availability impact means services remain online, but the trustworthiness of communications is compromised. European organizations in sectors such as finance, healthcare, government, and critical infrastructure, where secure communication is paramount, may face increased risks. Additionally, compliance with GDPR and other data protection regulations may be jeopardized if personal data is exposed or misused through this vulnerability.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Jul 2025, 06:26 UTC

Technical details

References

Community reviews

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