CVE-2026-81722High· 7.5▾ TwilightA flaw was found in the nltk PorterStemmer component. A remote attacker could exploit this vulnerability by providing a specially crafted, untrusted token. The inefficient algorithmic complexity in the stemming process, specifically within…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 41.3 · likelihood 0.1 · exploitation 0
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Exploit-prediction probability, daily snapshots since Sep 2.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via CSAF
0.4%
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Last analysed / modified upstream
A flaw was found in the nltk PorterStemmer component. A remote attacker could exploit this vulnerability by providing a specially crafted, untrusted token. The inefficient algorithmic complexity in the stemming process, specifically within the _is_consonant() and _measure() helper functions, causes excessive CPU usage when processing certain inputs. This can lead to a denial of service (DoS) condition, where the system becomes unresponsive for an extended period.
nltk: nltk PorterStemmer: Denial of Service due to inefficient token processing — rated Important by Red Hat. Released 2026-08-27, updated 2026-10-19.
Affected:
Fixed:
No fix planned:
Not affected:
For Red Hat OpenShift AI 3.3.7 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update:
https://docs.redhat.com/en/documentation/red_hat_openshift_ai/ https://access.redhat.com/errata/RHSA-2026:73987 For Red Hat OpenShift AI 3.4.5 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update:
https://docs.redhat.com/en/documentation/red_hat_openshift_ai/ https://access.redhat.com/errata/RHSA-2026:84734 For Red Hat OpenShift AI 3.5.1 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update:
https://docs.redhat.com/en/documentation/red_hat_openshift_ai/ https://access.redhat.com/errata/RHSA-2026:69539
Workarounds / mitigations:
Affected packages:
nltk <= 3.10.2Patched in:
nltk 3.10.3Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
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