CVE-2026-69249
DoS via exponential recursion in python-cryptography cert-chain validation.
Is CVE-2026-69249 being exploited?
Not confirmed. CVE-2026-69249 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 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-69249?
CVE-2026-69249 is rated High with a CVSS score of 8.7. 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-2026-69249?
Yes. A fix has been recorded for CVE-2026-69249. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-69249 affect?
CVE-2026-69249 affects python-cryptography <49.0.0, Python apps using cryptography for TLS/PKI validation, Servers performing certificate chain validation (e.g., TLS clients/servers). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-69249?
Upgrade to python-cryptography >=49.0.0; rate-limit and monitor certificate parsing.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Crafted certificate chains with duplicate self-signed certs cause exponential recursion, leading to CPU/time exhaustion and denial of service during cert validation.
Patch when possible
- affected>= 42.0.0 and < 49.0.0
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.