Red Hat Security Advisory: python3 security update
Affects Red Hat python3Source GCVE Database
Not known to be exploited · CVSS 8.7 High · fixed in Red Hat package updates : patch Red Hat CPython soon.
Data as of 1 Nov 2026, 01:56 UTC
- Patch
- Available – fixed in 3.15.0b4, 3.14.7, 3.13.15 +3
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 9 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 31 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Python Software FoundationCPython | Affected
| Fixed in
|
| Python Software FoundationCPython | Affected
| Fixed in
|
| Python Software FoundationCPython | Affected
| Fixed in
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| Python Software FoundationCPython | Affected
| Fixed in
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| Python Software FoundationCPython | Affected
| Fixed in
|
| Python Software FoundationCPython | Affected
| Fixed in
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Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released updated python3 packages for Red Hat Enterprise Linux 8.8 that fix this vulnerability. Users should apply the official Red Hat update as described in the advisory RHSA-2026:50064 and the referenced article https://access.redhat.com/articles/11258 to remediate the issue. No additional mitigation steps are required beyond applying the vendor-provided update.
Description
A denial of service vulnerability exists in the Python HTML parser due to repeated unterminated markup declarations. This vulnerability, tracked as CVE-2026-15308, can cause excessive CPU usage when processing crafted HTML content. Red Hat has issued a security update for python3 in Red Hat Enterprise Linux 8.8 to address this issue.