CVE-2025-67500

LOWCVSS 3.7/10EPSS 0.19%

Last modified

CVE-2025-67500 is a low-severity vulnerability rated 3.7/10 on the CVSS scale. Mastodon is a free, open-source social network server based on ActivityPub. Versions 4.2.27 and prior, 4.3.0-beta.1 through 4.3.14, 4.4.0-beta.1 through 4.4.9, 4.5.0-beta.1 through 4.5.2 have discrepancies in error handling which allow checking whether a given status exists by sending a request with a non-English Accept-Language header. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

Description

Mastodon is a free, open-source social network server based on ActivityPub. Versions 4.2.27 and prior, 4.3.0-beta.1 through 4.3.14, 4.4.0-beta.1 through 4.4.9, 4.5.0-beta.1 through 4.5.2 have discrepancies in error handling which allow checking whether a given status exists by sending a request with a non-English Accept-Language header. Using this behavior, an attacker who knows the identifier of a particular status they are not allowed to see can confirm whether this status exists or not. This cannot be used to learn the contents of the status or any other property besides its existence. This issue is fixed in versions 4.2.28, 4.3.15, 4.4.10 and 4.5.3.

Metrics

CVSS 3.1
3.7/10

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

EPSS Probability
0.19%

8.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
JoinmastodonMastodon< 4.2.28
JoinmastodonMastodon>= 4.3.0, < 4.3.15
JoinmastodonMastodon>= 4.4.0, < 4.4.10
JoinmastodonMastodon>= 4.5.0, < 4.5.3

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2025-67500?
Mastodon is a free, open-source social network server based on ActivityPub. Versions 4.2.27 and prior, 4.3.0-beta.1 through 4.3.14, 4.4.0-beta.1 through 4.4.9, 4.5.0-beta.1 through 4.5.2 have discrepancies in error handling which allow checking whether a given status exists by sending a request with a non-English Accept-Language header. Using this behavior, an attacker who knows the identifier of a particular status they are not allowed to see can confirm whether this status exists or not. This cannot be used to learn the contents of the status or any other property besides its existence. This issue is fixed in versions 4.2.28, 4.3.15, 4.4.10 and 4.5.3.
How severe is CVE-2025-67500?
CVE-2025-67500 has a CVSS score of 3.7/10 (LOW severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.
How do I fix CVE-2025-67500?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-67500?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST