CVE-2026-11972 is a denial of service vulnerability in the Python tarfile module affecting Red Hat Hardened Images. When processing tar archives in streaming mode ('r|'), the _Stream.seek function fails to properly detect the end-of-file condition, causing an infinite loop. This results in excessive CPU and memory consumption, leading to application denial of service. The vulnerability affects multiple python3.14 RPM packages on aarch64 and x86_64 architectures. Red Hat has issued updated packages (python3.14-3.14.6-1.2.hum1 and related) to fix this flaw.

Applications using the Python tarfile module in streaming mode to process untrusted tar archives may experience denial of service due to infinite loops caused by improper EOF handling. This results in high resource consumption (CPU and memory), potentially causing application slowdown or unresponsiveness. There is no impact on confidentiality or integrity, only availability is affected.

Red Hat has released updated python3.14 RPM packages that fix this vulnerability. Users should apply these updates to remediate the issue. Until patched, avoid using the tarfile module in streaming mode ('r|') with untrusted tar archives and prefer the standard file-based mode ('r') where possible.