VulnerabilityPublished 26 May 2026Updated 28 May 2026

CVE-2026-45575: oviva-ag epa4all-client · Improper Verification of Cryptographic Signature

Affects oviva-ag epa4all-clientSource CVE Database V5

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Not known to be exploited · CVSS 7.4 High : upgrade to 1.2.2 soon.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

7.4High

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.2.2

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: 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 26 May 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.

What to do

Upgrade epa4all-client and oviva-ag/epa4all-client to 1.2.2.

Affected software

Product	Affected	Fixed in
oviva-agepa4all-client	Affected <1.2.2	Fixed in 1.2.2
com.oviva.telematikepa4all-client	Affected <1.2.2	Fixed in 1.2.2
Mavenoviva-ag/epa4all-client`pkg:maven/oviva-ag/epa4all-client`Other threats	Affected <1.2.2	Fixed in 1.2.2

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

AI-suggested

Upgrade the epa4all-client to version 1.2.2 or later, where this vulnerability is fixed. Since the vulnerability requires MITM capability within the TI network, ensuring secure TLS connections and network protections can reduce risk. Patch status is not explicitly stated in vendor advisories, but the description confirms the fix is included in version 1.2.2. No additional vendor mitigation guidance is available.

Description

CVE-2026-45575 is a high-severity vulnerability in the oviva-ag epa4all-client Java client used in the Telematik Infrastruktur. Versions prior to 1.2.2 are affected by improper verification of cryptographic signatures (CWE-347). An attacker capable of performing a man-in-the-middle (MITM) attack on the TLS connection within the TI network can substitute a forged discovery document. This document redirects critical URIs to attacker-controlled endpoints, enabling capture of signed authentication material. The vulnerability is fixed in version 1.2.2.

Impact

Successful exploitation allows an attacker with MITM capability on the TLS connection within the TI network to capture signed authentication material by redirecting cryptographic key URIs to attacker-controlled endpoints. This compromises the confidentiality and integrity of authentication data, potentially enabling unauthorized access or impersonation within the affected infrastructure. There is no indication of impact on availability. No known exploits in the wild have been reported.

Summary

The epa4all-client prior to version 1.2.2 does not properly verify cryptographic signatures on discovery documents received from the identity provider (IDP). This allows an attacker who can intercept and modify the TLS connection within the Telematik Infrastruktur network to replace the discovery document with a forged one. The forged document redirects the URIs for encryption and signature public keys to attacker-controlled URLs. Consequently, the client encrypts the signed challenge response to the attacker's key and sends it to the attacker's authentication endpoint, exposing signed authentication material. This flaw is classified under CWE-347 (Improper Verification of Cryptographic Signature) and has a CVSS 3.1 score of 7.4 (high). The issue is resolved in epa4all-client version 1.2.2.

CWE-347Improper Verification of Cryptographic Signature (opens in a new tab)
Base weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
OWASP Cheat Sheets
XML Security (opens in a new tab)
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
REST Assessment (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.2 (opens in a new tab)
V3.5.3 (opens in a new tab)
V13.2.6 (opens in a new tab)
Attack patterns
Padding Oracle Crypto Attack (opens in a new tab)
Signature Spoofing by Improper Validation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Jun 2026, 20:49 UTC

WeaknessesCWE-347

Technical details

References

Community reviews

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