# CVE-2026-95691: OpenSSL use-after-free in QUIC CRYPTO frame handling

Source: https://junglewise.ai/threats/cve-2026-95691-issue-summary-a-retransmitted-quic-crypto-frame-can-release  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-95691 · Severity: info · Published 2026-11-10

OpenSSL's QUIC implementation (used for secure communications) contains a memory safety flaw where retransmitted CRYPTO frames can release memory that the TLS handshake layer still has a pointer to. A malicious QUIC server can exploit this to crash the client or leak small amounts of heap memory data.

Technologies: [OpenSSL](https://junglewise.ai/threats/technologies/openssl). Vendors: [OpenSSL](https://junglewise.ai/threats/vendors/openssl).

## Quick answers

**Is CVE-2026-95691 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-95691 being exploited in the wild.

**How severe is CVE-2026-95691?** Informational severity, published 10 November 2026.

**Which products and versions are affected?** OpenSSL versions with QUIC support prior to the fix.

**Is there a fix for CVE-2026-95691?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-95691 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-95691?** Check whether you run OpenSSL at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A use-after-free in the QUIC stream reassembly module (quic_strm_reas) occurs when a retransmitted CRYPTO frame fully overlaps an existing frame, causing the old buffer to be freed while the TLS record layer (ssl3_read_bytes via quic_read_record) retains a direct pointer to it obtained via ossl_sframe_set_peek(). The fix introduces a range locking mechanism to prevent overlapping stream frames from releasing locked buffers, eliminating the stale pointer condition.

## Affected products

- OpenSSL OpenSSL versions with QUIC support prior to the fix

## Timeline

- 2026-11-10: disclosed

## References

- [https://github.com/openssl/openssl/commit/dd90ceb99a3c2ddba336bb4a00be9ebabd84c2a1](https://github.com/openssl/openssl/commit/dd90ceb99a3c2ddba336bb4a00be9ebabd84c2a1)
- [https://github.com/openssl/openssl/commit/ec9d4de9d03989b29db5a3d7efdb4c285deaf386](https://github.com/openssl/openssl/commit/ec9d4de9d03989b29db5a3d7efdb4c285deaf386)

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