### Impact An attacker can cause the creation of unnecessary background threads in the python-engineio server by exploiting the heartbeat mechanism, which launches a thread when a new connection is received, and when the client sends a PONG packet. Note: this issue primarily affects synchronous servers. Asynchronous servers allocate background tasks instead of physical threads, which are lightweight and less likely to cause denial of service. However, the fix that was implemented was also applied to the asynchronous case. ### Patches Version 4.13.2 addresses this issue as follows: - The initial background thread (or async task( for heartbeat management is only launched if a client passes authentication in the `connect` handler. - The server now ensures that there is only one background heatbeat thread (or async task) per client at a given point in time. Out of sequence PONG packets are now discarded when an active heartbeat thread is already running.
Update python-engineio to 4.13.2 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanpython-engineio has unbound thread allocation that can cause denial of service affects python-engineio (pip). Severity is high. ### Impact An attacker can cause the creation of unnecessary background threads in the python-engineio server by exploiting the heartbeat mechanism, which launches a thread when a new connection is received, and when the client sends a PONG packet. Note: this issue primarily affects synchronous servers. Asynchronous servers allocate background tasks instead of physical threads, which are lightweight and less likely to cause denial of service. However, the fix that was implemented was also applied to the asynchronous case. ### Patches Version 4.13.2 addresses this issue as follows: - The initial background thread (or async task( for heartbeat management is only launched if a client passes authentication in the `connect` handler. - The server now ensures that there is only one background heatbeat thread (or async task) per client at a given point in time. Out of sequence PONG packets are now discarded when an active heartbeat thread is already running.
AI coding agents often install or upgrade packages automatically in pip. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
### Impact An attacker can cause the creation of unnecessary background threads in the python-engineio server by exploiting the heartbeat mechanism, which launches a thread when a new connection is received, and when the client sends a PONG packet. Note: this issue primarily affects synchronous servers. Asynchronous servers allocate background tasks instead of physical threads, which are lightweight and less likely to cause denial of service. However, the fix that was implemented was also applied to the asynchronous case. ### Patches Version 4.13.2 addresses this issue as follows: - The initial background thread (or async task( for heartbeat management is only launched if a client passes authentication in the `connect` handler. - The server now ensures that there is only one background heatbeat thread (or async task) per client at a given point in time. Out of sequence PONG packets are now discarded when an active heartbeat thread is already running.
Update python-engineio to 4.13.2 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanpython-engineio has unbound thread allocation that can cause denial of service affects python-engineio (pip). Severity is high. ### Impact An attacker can cause the creation of unnecessary background threads in the python-engineio server by exploiting the heartbeat mechanism, which launches a thread when a new connection is received, and when the client sends a PONG packet. Note: this issue primarily affects synchronous servers. Asynchronous servers allocate background tasks instead of physical threads, which are lightweight and less likely to cause denial of service. However, the fix that was implemented was also applied to the asynchronous case. ### Patches Version 4.13.2 addresses this issue as follows: - The initial background thread (or async task( for heartbeat management is only launched if a client passes authentication in the `connect` handler. - The server now ensures that there is only one background heatbeat thread (or async task) per client at a given point in time. Out of sequence PONG packets are now discarded when an active heartbeat thread is already running.
AI coding agents often install or upgrade packages automatically in pip. A high vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package |
|---|
| Affected range |
|---|
| Fixed version |
|---|
| python-engineiopip | <=4.13.1 | 4.13.2 |
|---|
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard| Package |
|---|
| Affected range |
|---|
| Fixed version |
|---|
| python-engineiopip | <=4.13.1 | 4.13.2 |
|---|
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard