CVE-2026-95692: OpenSSL out-of-bounds read

Summary

Issue summary: Setting an AES-GCM-SIV IV shorter than the expected nonce length via EVP_CipherInit_ex() may trigger a heap out-of-bounds read. Supplying a longer IV is silently truncated instead of rejected.

Impact summary: An application passing a caller-supplied IV of the wrong length may crash or read beyond its buffer. Because trailing IV bytes are ignored, an attacker who knows one message and tag may forge messages under a different IV.

CWE: CWE-125: Out-of-bounds Read

Show the full description

Description: AES-GCM-SIV copies the caller-supplied IV or nonce into its internal state using a copy whose length is taken from the expected nonce size rather than from the length the caller actually provided. When the caller passes a shorter IV, the copy reads past the end of the caller's buffer; AddressSanitizer confirms a heap out-of-bounds read reached through EVP_CipherInit_ex() into ossl_aes_gcm_siv_init(). When the caller passes a longer IV, the implementation silently discards the trailing bytes instead of rejecting the length.

The truncation breaks the binding between the IV and the computed authentication tag. An attacker who has observed a message and its tag under one IV can produce a message and tag that verify under a different IV whose first bytes match, since the surplus bytes never influence the computation. The message itself is unchanged, so this is a failure of IV commitment rather than a classic existential forgery.

Only applications that call EVP_CipherInit_ex() (or the equivalent provider cipher initialization) with an IV length other than the standard 12 bytes for AES-GCM-SIV are affected. The severity is limited because the out-of-bounds read is small and attacker-controlled only in length, and the forgery requires an unusual IV length choice by the application.

FIPS impact: no The FIPS modules are not affected by this issue, as AES-GCM-SIV is not an approved algorithm.

cve.now Index

21Pcve.now Index 21 of 100 · methodology v3 · provisional

Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
Exposure?/25Unknown. No advisory context yet
Reach20/20Affects OpenSSL (software on nearly every server, desktop or phone)
Severity1/10Rated low by openssl
No patch0/5No signal

What would change the score

Would score about 76 if added to CISA KEV
Would score about 71 if CISA's SSVC rates exploitation active
Would score about 43 if advisories confirm default setups are exposed

How the score works · Rankings

What to do

Upgrade to a fixed version: 4.1.1, 4.0.4, 3.5.10.

Check your systems with an agent

Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.

Check whether my systems are affected by CVE-2026-95692 (Out-of-Bounds Read and Incorrect IV Length Handling in AES-GCM-SIV), 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-2026-95692 (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-2026-95692 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-95692 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/70a47ac78b6f3be1b22fb1551bd0bfcff4f29613
- https://github.com/openssl/openssl/commit/510872388f5d145cf870868b3d288a23822cb776
- https://github.com/openssl/openssl/commit/257a3427aa0ef8d9dd2ef5b3e2d1c021a221b116
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.

Entry: https://cve.now/CVE-2026-95692
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-2026-95692.

Timeline

Nov 10, 2026, 6:16 PM UTCCVE published
Nov 10, 2026, 8:58 PM UTCFirst seen by cve.now

Affected versions

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

Evidence 6

CVE record · 2

Establishes: The identifier and description.

Record
CVE List · CVE-2026-95692
Record
NVD · CVE-2026-95692

Corrections

None so far.

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Questions about CVE-2026-95692

Is CVE-2026-95692 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: cve.now feed data

Which versions are affected by CVE-2026-95692?

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: cve.now feed data

How do I fix CVE-2026-95692?

Upgrade to a fixed version: 4.1.1, 4.0.4, 3.5.10.Source: cve.now feed data

Out-of-Bounds Read and Incorrect IV Length Handling in AES-GCM-SIV