CVE-2026-28481
OpenClaw < 2026.2.1 - Bearer Token Leakage via MS Teams Attachment Downloader Suffix Matching
OpenClaw versions 2026.1.30 and earlier, contain an information disclosure vulnerability, patched in 2026.2.1, in the MS Teams attachment downloader (optional extension must be enabled) that leaks bearer tokens to allowlisted suffix domains. When retrying downloads after receiving 401 or 403 responses, the application sends Authorization bearer tokens to untrusted hosts matching the permissive suffix-based allowlist, enabling token theft.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Active
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
OpenClaw < 2026.2.1 - Bearer Token Leakage via MS Teams Attachment Downloader Suffix Matching
OpenClaw versions 2026.1.30 and earlier, contain an information disclosure vulnerability, patched in 2026.2.1, in the MS Teams attachment downloader (optional extension must be enabled) that leaks bearer tokens to allowlisted suffix domains. When retrying downloads after receiving 401 or 403 responses, the application sends Authorization bearer tokens to untrusted hosts matching the permissive suffix-based allowlist, enabling token theft.
- Record
CVE-2026-28481- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-201
- Updated
- 2026-11-02
EUVDEUVD-2026-9927
OpenClaw versions 2026.1.30 and earlier, contain an information disclosure vulnerability, patched in 2026.2.1, in the MS Teams attachment downloader (optional extension must be enabled) that leaks bearer tokens to allowlisted suffix domains. When retrying downloads after receiving 401 or 403 responses, the application sends Authorization bearer tokens to untrusted hosts matching the permissive suffix-based allowlist, enabling token theft.
- Record
EUVD-2026-9927- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-7vwx-582j-j332
OpenClaw MS Teams inbound attachment downloader leaks bearer tokens to allowlisted suffix domains
Summary
NOTE: This only affects deployments that enable the optional MS Teams extension (Teams channel). If you do not use MS Teams, you are not impacted.
When OpenClaw downloads inbound MS Teams attachments / inline images, it may retry a URL with an Authorization: Bearer <token> header after receiving 401 or 403.
Because the default download allowlist uses suffix matching (and includes some multi-tenant suffix domains), a message that references an untrusted but allowlisted host could cause that bearer token to be sent to the wrong place.
Affected Packages / Versions
- Package:
openclaw(npm) - Vulnerable:
<= 2026.1.30 - Patched:
>= 2026.2.1
Fix
- Fix commit:
41cc5bcd4f1d434ad1bbdfa55b56f25025ecbf6b - Upgrade to
openclaw >= 2026.2.1
Workarounds
- If you do not need MS Teams, disable the MS Teams extension.
- If you must stay on an older version, ensure the auth host allowlist is strict (only Microsoft-owned endpoints that require auth) and avoid wildcard or broad suffix entries.
Credits
Thanks @yueyueL for reporting.
- Record
GHSA-7vwx-582j-j332- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N - Weakness
- CWE-201
- Updated
- 2026-11-02
NVD
OpenClaw versions 2026.1.30 and earlier, contain an information disclosure vulnerability, patched in 2026.2.1, in the MS Teams attachment downloader (optional extension must be enabled) that leaks bearer tokens to allowlisted suffix domains. When retrying downloads after receiving 401 or 403 responses, the application sends Authorization bearer tokens to untrusted hosts matching the permissive suffix-based allowlist, enabling token theft.
- Record
CVE-2026-28481- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-201
- Updated
- 2026-11-02
OSV
OpenClaw < 2026.2.1 - Bearer Token Leakage via MS Teams Attachment Downloader Suffix Matching
OpenClaw versions 2026.1.30 and earlier, contain an information disclosure vulnerability, patched in 2026.2.1, in the MS Teams attachment downloader (optional extension must be enabled) that leaks bearer tokens to allowlisted suffix domains. When retrying downloads after receiving 401 or 403 responses, the application sends Authorization bearer tokens to untrusted hosts matching the permissive suffix-based allowlist, enabling token theft.
- Record
CVE-2026-28481- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-201
- Updated
- 2026-11-02
OSVGHSA-7vwx-582j-j332
OpenClaw MS Teams inbound attachment downloader leaks bearer tokens to allowlisted suffix domains
Summary
NOTE: This only affects deployments that enable the optional MS Teams extension (Teams channel). If you do not use MS Teams, you are not impacted.
When OpenClaw downloads inbound MS Teams attachments / inline images, it may retry a URL with an Authorization: Bearer <token> header after receiving 401 or 403.
Because the default download allowlist uses suffix matching (and includes some multi-tenant suffix domains), a message that references an untrusted but allowlisted host could cause that bearer token to be sent to the wrong place.
Affected Packages / Versions
- Package:
openclaw(npm) - Vulnerable:
<= 2026.1.30 - Patched:
>= 2026.2.1
Fix
- Fix commit:
41cc5bcd4f1d434ad1bbdfa55b56f25025ecbf6b - Upgrade to
openclaw >= 2026.2.1
Workarounds
- If you do not need MS Teams, disable the MS Teams extension.
- If you must stay on an older version, ensure the auth host allowlist is strict (only Microsoft-owned endpoints that require auth) and avoid wildcard or broad suffix entries.
Credits
Thanks @yueyueL for reporting.
- Record
GHSA-7vwx-582j-j332- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N - Weakness
- CWE-201
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
openclawnpm | before 2026.2.1 | 2026.2.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-28481 is a medium vulnerability (CVSS 5.9) in Openclaw, published February 17, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.30%, the 23rd percentile. Fixed in openclaw 2026.2.1.
References
github.com/openclaw/openclaw/security/advisories/GHSA-7vwx-582j-j332
vulncheck.com/advisories/openclaw-bearer-token-leakage-via-ms-teams-attachment-downloader-suffix-matching
nvd.nist.gov/vuln/detail/CVE-2026-28481