CVE-2026-25540

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Source
https://cve.org/CVERecord?id=CVE-2026-25540
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25540.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-25540
Aliases
Published
2026-02-04T21:42:09.460Z
Modified
2026-03-13T04:10:59.189014Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L CVSS Calculator
Summary
Mastodon's signature-dependent ActivityPub collection responses cached under signature-independent keys (Web Cache Poisoning via `Rails.cache`)
Details

Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.3.19, 4.4.13, 4.5.6, Mastodon is vulnerable to web cache poisoning via `Rails.cache. When AUTHORIZED_FETCH is enabled, the ActivityPub endpoints for pinned posts and featured hashtags have contents that depend on the account that signed the HTTP request. However, these contents are stored in an internal cache and reused with no regards to the signing actor. As a result, an empty response generated for a blocked user account may be served to requests from legitimate non-blocked actors, or conversely, content intended for non-blocked actors may be returned to blocked actors. This issue has been patched in versions 4.3.19, 4.4.13, 4.5.6.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-524"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25540.json"
}
References

Affected packages

Git / github.com/mastodon/mastodon

Affected ranges

Type
GIT
Repo
https://github.com/mastodon/mastodon
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
02c9c71294321e35261036a11531a5e42d70aea8
Fixed
3871f3a3996d2832f66b1c219ae2f334e3e4c205
Fixed
e8045de79bf0b445f43a7b7b7e5b38919edd93f6
Database specific 
{
    "versions": [
        {
            "introduced": "0"
        },
        {
            "fixed": "4.3.19"
        },
        {
            "fixed": "4.4.13"
        },
        {
            "fixed": "4.5.6"
        }
    ]
}

Affected versions

v0.*
v0.1.0
v0.1.1
v0.1.2
v0.6
v0.7
v0.8
v0.9
v0.9.9
v1.*
v1.0
v1.1
v1.1.1
v1.1.2
v1.2
v1.2.1
v1.2.2
v1.3
v1.3.1
v1.3.2
v1.4.1
v1.4.2
v1.4.3
v1.4.4
v1.4.5
v1.4.6
v1.4.7
v1.4rc1
v1.4rc2
v1.4rc3
v1.4rc4
v1.4rc5
v1.4rc6
v1.5.0
v1.5.0rc1
v1.5.0rc2
v1.5.0rc3
v1.5.1
v1.6.0
v1.6.0rc1
v1.6.0rc2
v1.6.0rc3
v1.6.0rc4
v1.6.0rc5
v1.6.1
v2.*
v2.0.0
v2.0.0rc1
v2.0.0rc2
v2.0.0rc3
v2.0.0rc4
v2.1.0
v2.1.0rc1
v2.1.0rc2
v2.1.0rc3
v2.1.0rc4
v2.1.0rc5
v2.1.0rc6
v2.1.1
v2.1.2
v2.1.3
v2.2.0
v2.2.0rc1
v2.2.0rc2
v2.3.0
v2.3.0rc1
v2.3.0rc2
v2.3.0rc3
v2.3.1
v2.3.1rc1
v2.3.1rc2
v2.3.1rc3
v2.3.2
v2.3.2rc1
v2.3.2rc2
v2.3.2rc3
v2.3.2rc4
v2.3.2rc5
v2.4.0
v2.4.0rc1
v2.4.0rc2
v2.4.0rc3
v2.4.0rc4
v2.4.0rc5
v2.4.1
v2.4.1rc1
v2.4.1rc2
v2.4.1rc3
v2.4.1rc4
v2.4.2
v2.4.2rc1
v2.4.2rc2
v2.4.2rc3
v2.4.3
v2.4.3rc1
v2.4.3rc2
v2.4.3rc3
v2.5.0
v2.5.0rc1
v2.5.0rc2
v2.6.0
v2.6.0rc1
v2.6.0rc2
v2.6.0rc3
v2.6.0rc4
v2.6.1
v2.7.0
v2.7.0rc1
v2.7.0rc2
v2.7.0rc3
v2.7.1
v2.8.0
v2.8.0rc1
v2.8.0rc2
v2.8.0rc3
v2.8.1
v2.8.2
v2.9.0
v2.9.0rc1
v2.9.0rc2
v2.9.1
v2.9.2
v3.*
v3.0.0
v3.0.0rc1
v3.0.0rc2
v3.0.0rc3
v3.0.1
v3.1.0
v3.1.0rc1
v3.1.0rc2
v3.1.1
v3.1.2
v3.1.3
v3.1.4
v3.2.0
v3.2.0rc1
v3.2.0rc2
v3.3.0
v3.3.0rc1
v3.3.0rc2
v3.3.0rc3
v3.4.0
v3.4.0rc1
v3.4.0rc2
v3.4.1
v3.5.0
v3.5.0rc1
v3.5.0rc2
v3.5.0rc3
v3.5.1
v3.5.2
v3.5.3
v4.*
v4.0.0
v4.0.0rc1
v4.0.0rc2
v4.0.0rc3
v4.0.0rc4
v4.0.1
v4.0.2
v4.1.0
v4.1.0rc1
v4.1.0rc2
v4.1.0rc3
v4.2.0
v4.2.0-beta1
v4.2.0-beta2
v4.2.0-beta3
v4.2.0-rc1
v4.2.0-rc2
v4.3.0
v4.3.0-beta.1
v4.3.0-beta.2
v4.3.0-rc.1
v4.3.1
v4.3.10
v4.3.11
v4.3.12
v4.3.13
v4.3.14
v4.3.15
v4.3.16
v4.3.17
v4.3.18
v4.3.2
v4.3.3
v4.3.4
v4.3.5
v4.3.6
v4.3.7
v4.3.8
v4.3.9
v4.4.0
v4.4.0-beta.1
v4.4.0-beta.2
v4.4.0-rc.1
v4.4.1
v4.4.10
v4.4.11
v4.4.12
v4.4.2
v4.4.3
v4.4.4
v4.4.5
v4.4.6
v4.4.7
v4.4.8
v4.4.9
v4.5.0
v4.5.0-beta.1
v4.5.0-beta.2
v4.5.0-rc.1
v4.5.0-rc.2
v4.5.0-rc.3
v4.5.1
v4.5.2
v4.5.3
v4.5.4
v4.5.5

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25540.json"

Git / github.com/tootsuite/mastodon

Affected ranges

Type
GIT
Repo
https://github.com/tootsuite/mastodon
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
02c9c71294321e35261036a11531a5e42d70aea8
Introduced
69e14246b838443985a541e97327494b8d2fdffb
Fixed
3871f3a3996d2832f66b1c219ae2f334e3e4c205
Introduced
26c78392f88afccebb8a88b68bc9994a9ce12648
Fixed
e8045de79bf0b445f43a7b7b7e5b38919edd93f6
Database specific 
{
    "versions": [
        {
            "introduced": "0"
        },
        {
            "fixed": "4.3.19"
        },
        {
            "introduced": "4.4.0"
        },
        {
            "fixed": "4.4.13"
        },
        {
            "introduced": "4.5.0"
        },
        {
            "fixed": "4.5.6"
        }
    ]
}

Affected versions

v4.*
v4.4.0
v4.4.1
v4.4.10
v4.4.11
v4.4.12
v4.4.2
v4.4.3
v4.4.4
v4.4.5
v4.4.6
v4.4.7
v4.4.8
v4.4.9
v4.5.0
v4.5.1
v4.5.2
v4.5.3
v4.5.4
v4.5.5

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25540.json"