How severe is CVE-2026-5557?

CVE-2026-5557 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-5557 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-5557?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-5557 have an EU (EUVD) identifier?

Yes. CVE-2026-5557 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19062.

When was CVE-2026-5557 published?

CVE-2026-5557 was published on 2026-04-05 and last updated on 2026-06-17.

CVE-2026-5557

CVE-2026-5557 is a medium-severity vulnerability with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v2: 6.5
CVSS v4: 2.1
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-19062
Weakness: CWE-287
Published: 2026-04-05
Last modified: 2026-06-17

Description

A vulnerability was detected in badlogic pi-mono up to 0.58.4. This issue affects some unknown processing of the file packages/mom/src/slack.ts of the component pi-mom Slack Bot. The manipulation results in authentication bypass using alternate channel. The attack can be executed remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Frequently asked questions

What is CVE-2026-5557?: A vulnerability was detected in badlogic pi-mono up to 0.58.4. This issue affects some unknown processing of the file packages/mom/src/slack.ts of the component pi-mom Slack Bot. The manipulation results in authentication bypass using alternate channel. The attack can be executed remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
How severe is CVE-2026-5557?: CVE-2026-5557 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-5557 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-5557?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-5557 have an EU (EUVD) identifier?: Yes. CVE-2026-5557 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19062.
When was CVE-2026-5557 published?: CVE-2026-5557 was published on 2026-04-05 and last updated on 2026-06-17.

References

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-45480 — Critical (CVSS 10.0): Improper authentication in Azure Active Directory allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-46389 — Critical (CVSS 10.0): UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS…
CVE-2026-10611 — Critical (CVSS 10.0): An authentication bypass vulnerability exists in MISP when LDAP mixed authentication is enabled with OTP enforcement.…
CVE-2026-47280 — Critical (CVSS 10.0): Improper authentication in Azure Resource Manager (ARM) allows an unauthorized attacker to elevate privileges over a…
CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

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