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Fencer Intel
high 7.7

CVE-2026-73530 json

Flyto2 Core < 2.28.0 SSRF Guard Bypass via is_private_ip()

published 2mo ago modified 2mo ago also EUVD-2026-58242 , GHSA-gc4h-hj7x-gp5p

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository flytohub/flyto-core. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
7.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

Flyto2 Core before 2.28.0 contains a server-side request forgery guard bypass vulnerability that allows attackers to reach internal services by supplying URLs using the unblocked IPv6 address `::` which the kernel routes to loopback identically to `0.0.0.0`. Attackers can submit requests or trigger 302 redirects to ` to bypass the private IP range and blocked hostname checks in `is_private_ip()`, reaching services bound to IPv6 loopback across the `http.get`, `http.request`, and `http.batch` modules.

Patch / fix

  • flytohub flyto-core 2.28.0

Is CVE-2026-73530 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/flytohub/flyto-core/security/advisories/GHSA-gc4h-hj7x-gp5p referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N
CNA 3.1 7.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/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 7.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Inferred packages

No advisory lists a package for this vulnerability yet. The CVE names these as products and links their GitHub repository, and the package registry names the same repository, so they are probably the affected packages. Low confidence: the versions are the CVE’s own for the product, and a stack check reports the package as unchecked when there are none.

ecosystem package repository affected
pypi flyto-core flytohub/flyto-core no versions given

Affected products

  • flytohub flyto-core

Classification

Weakness
  • CWE-918 Server-Side Request Forgery

References

Sources

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.

The maintainers of flytohub/flyto-core published their own advisory on GitHub. Reviewed sources take precedence over it.