Red Hat Security Advisory: python3.9 security update
Affects Red Hat python3.9Source GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 4.3 Medium.
Data as of 30 Oct 2026, 00:29 UTC
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:LExploitation evidence
Disclosed: evidence found.
CVE published 17 Jun 2025
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 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
PyPIcpythonpkg:pypi/cpythonOther threats | Affected
| Fixed in– |
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 python3.9 packages for Red Hat Enterprise Linux 9.4 that fix these vulnerabilities. Users should apply the provided security update as detailed in the Red Hat advisory RHSA-2026:74087. No additional mitigation steps are indicated beyond applying the official patch.
Description
Multiple security vulnerabilities affecting Python 3.9 in Red Hat Enterprise Linux 9.4 have been addressed. These include issues causing quadratic complexity in HTMLParser and os.path.expandvars(), a tarfile extraction filter bypass allowing directory escape, and a CPU denial of service via repeated unterminated markup declarations in the HTML parser. Red Hat has released an important security update to mitigate these issues.
References
- access.redhat.com/errata/RHSA-2026:74087 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2373234 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2408891 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2491848 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2498608 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_74087.json (opens in a new tab)