CVE-2026-91988 json
atomic-agents-stack before 1.1.0 Remote Code Execution via HTTP MCP
published 2mo ago modified last mo. also GHSA-xhcr-cqfr-m3hv , EUVD-2026-78659
- cvss
- 8.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 25%
- public exploits
- 0
- none known
Summary
atomic-agents-stack before 1.1.0 accepts cleartext HTTP schemes in the HTTP MCP server-registry backend factory, allowing network man-in-the-middle attackers to rewrite catalog responses. Attackers can inject arbitrary command and argument values that are spawned as local subprocesses by MCPClientPool to achieve code execution on the agent host.
Patch / fix
- pypi atomic-agents-stack 1.1.0
- dep0we atomic-agents-stack 1.1.0
Is CVE-2026-91988 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- last mo.
Exploit prediction
0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.2 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 9.2 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/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 |
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | atomic-agents-stack | <1.1.0 |
1.1.0 |
Affected products
- dep0we atomic-agents-stack
Classification
References
-
github.com
/dep0we/atomic-agents-stack/security/advisories/GHSA-xhcr-cqfr-m3hv
vendor-advisory, web
-
vulncheck.com
/advisories/atomic-agents-stack-before-1.1.0-remote-code-execution-via-http-mcp
third-party-advisory
-
github.com
/dep0we/atomic-agents-stack
package
-
github.com
/dep0we/atomic-agents-stack/releases#release-v1.1.0
web
Sources
- CVE List CVE-2026-91988
- GitHub Advisory GHSA-xhcr-cqfr-m3hv
- NVD CVE-2026-91988
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.