CVE-2025-48937VulnerabilityPublished 10 Jun 2025

CVE-2025-48937: matrix-rust-sdk · Authentication Bypass by Spoofing

Affects matrix-rust-sdkSource CVE Database V5

Not known to be exploited · CVSS 4.9 Medium : upgrade to 0.11.1 when convenient.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 3.1 base score

4.9Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 30% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.11.1

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
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: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 Jun 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 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

Upgrade matrix-org/matrix-rust-sdk to 0.11.1.

Affected software

Product	Affected	Fixed in
crates.iomatrix-org/matrix-rust-sdk`pkg:cargo/matrix-org/matrix-rust-sdk`Other threats	Affected >=0.8.0 <0.11.1	Fixed in 0.11.1

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

AI-suggested

European organizations should immediately verify the versions of matrix-rust-sdk in use and upgrade to version 0.11.1 or later where the vulnerability is fixed. Since the issue arises from malicious homeserver operators, organizations should also: 1) Restrict federation to trusted homeservers only, implementing strict access controls and vetting procedures for federated servers. 2) Monitor and audit homeserver logs for unusual event modifications or suspicious activity indicative of spoofing attempts. 3) Employ additional cryptographic verification or out-of-band validation for critical communications to detect spoofed messages. 4) Educate users about the risks of message spoofing and encourage verification of unexpected or sensitive messages. 5) Consider deploying network-level protections and anomaly detection systems to identify compromised homeservers or abnormal traffic patterns. 6) Engage with Matrix community and vendors for timely updates and security advisories. These steps go beyond generic patching by addressing the federated trust model and operational security controls necessary to mitigate risks from malicious homeservers.

Description

matrix-rust-sdk is an implementation of a Matrix client-server library in Rust.matrix-sdk-crypto since version 0.8.0 and up to 0.11.0 does not correctly validate the sender of an encrypted event. Accordingly, a malicious homeserver operator can modify events served to clients, making those events appear to the recipient as if they were sent by another user. This vulnerability is fixed in 0.11.1 and 0.12.0.

Impact

For European organizations using Matrix-based communication platforms that rely on the matrix-rust-sdk, this vulnerability could allow a malicious or compromised homeserver operator to impersonate users by spoofing encrypted events. This undermines trust in message authenticity and could facilitate social engineering, misinformation, or unauthorized command execution within collaborative environments. While confidentiality is not directly affected, the integrity breach can lead to significant operational risks, especially in sectors requiring strong non-repudiation and audit trails such as government, finance, healthcare, and critical infrastructure. The federated nature of Matrix means that organizations federating with untrusted or compromised homeservers are particularly at risk. This could impact inter-organizational communications and collaboration platforms widely used in Europe. The vulnerability does not enable denial of service or data leakage but can erode confidence in secure communications, potentially leading to reputational damage and compliance issues under regulations like GDPR if trust in communication authenticity is compromised.

CWE-290Authentication Bypass by Spoofing (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
OWASP Cheat Sheets
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V3.5.1 (opens in a new tab)
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
Attack patterns
Creating a Rogue Certification Authority Certificate (opens in a new tab)
Web Services API Signature Forgery Leveraging Hash Function Extension Weakness (opens in a new tab)
Signature Spoof (opens in a new tab)
Signature Spoofing by Misrepresentation (opens in a new tab)
Session Credential Falsification through Prediction (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 10 Jul 2025, 23:34 UTC

WeaknessesCWE-290

Technical details

References

Community reviews

Related threats