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Fencer Intel
high 7.5

CVE-2026-54635 json

pytonapi has a Webhook Custom Path Authentication Bypass

published 3mo ago modified 19d ago also GHSA-3fcr-jvgp-7f58 , PYSEC-2026-3614 , EUVD-2026-49907

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

pytonapi is a Python SDK for TONAPI that provides REST API, streaming, and webhook access to the TON blockchain. From 2.0.0 to 2.2.0, TonapiWebhookDispatcher fails to validate the Authorization header when a webhook handler is registered with the documented path argument, because setup() stores bearer tokens only under the default suffix paths and never adds the custom path to the token map, so self._tokens.get(path) returns None and the authentication guard is skipped. An unauthenticated remote attacker can POST forged payloads to the custom webhook endpoint and trigger victim-defined handlers. This issue is fixed in version 2.2.1.

Patch / fix

Is CVE-2026-54635 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.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
3mo ago

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/nessshon/tonapi/security/advisories/GHSA-3fcr-jvgp-7f58 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
pypi pytonapi
>=2.0.0, <2.2.1
2.2.1

Affected products

  • nessshon tonapi

Classification

Weakness

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.