CVE-2026-9669
BZ2Decompressor reuse after error can cause out-of-bounds writes and crash.
Is CVE-2026-9669 being exploited?
Not confirmed. CVE-2026-9669 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.68% probability of exploitation in the next 30 days.
How severe is CVE-2026-9669?
CVE-2026-9669 is rated High with a CVSS score of 8.2. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-9669?
Not known from our data. No patch reference has been recorded for CVE-2026-9669, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-9669 affect?
CVE-2026-9669 affects Python bz2 module (standard library). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-9669?
Monitor; plan patch when available; audit untrusted bz2 usage.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
DoS: crafted input may crash the process via out-of-bounds writes during decompression.
Monitor only
- affected< 3.10.21
- affected>= 3.11.0 and < 3.11.16
- affected>= 3.12.0 and < 3.12.14
- affected>= 3.13.0 and < 3.13.14
- affected>= 3.14.0 and < 3.14.6
- affected>= 3.15.0a1 and < 3.15.0b3
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.