CVE-2026-88822: OpenSSL uninitialized variable

Summary

Issue summary: QUIC, when performing automated peer detection, may allow uninitialized stack data to leak into the received address which is then used as the destination for outgoing packets.

Impact summary: Applications using QUIC's automated peer detection mechanism may receive an invalid address, leading to connection loss and disclosure of uninitialized stack data to an attacker observing the outgoing network traffic.

CWE: CWE-457 (Use of Uninitialized Variable)

Show the full description

Description: The OpenSSL QUIC stack contains a feature in which, when using an already connected socket, it will auto-detect the peer address during the SSL handshake. This feature uses the getpeername() function, passing a buffer of sufficient length to hold any supported address family, but passes a buffer length that is only sized such that larger addresses, such as IPv6, cannot be retrieved. The getpeername() function however, still returns the full address length, which is accepted as the valid input buffer length, leading to the address buffer containing uninitialized stack data instead of the actual peer address. The invalid peer address is then used as destination for the outgoing packets which leads to a connectivity breakage and a leakage of the uninitialized stack data to passive network observers.

FIPS impact: no The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this CVE as the affected protocol is not implemented in the FIPS module.

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-2026-88822 (QUIC Uses Uninitialized Stack Bytes During Automated Peer Detection), 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-2026-88822 (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-2026-88822 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-88822 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/7b4f5344aa0401e7b777640050b5257ed2a70e88
- https://github.com/openssl/openssl/commit/911eee8eb7550b95a206f1ad8cbdb986098982f3
- https://github.com/openssl/openssl/commit/1a73dc590cbad62d6f0329ea4779eadaa8d8fd75
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-2026-88822
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-2026-88822.

Timeline

Nov 10, 2026, 6:15 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-2026-88822
Record
NVD · CVE-2026-88822

Corrections

None so far.

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Questions about CVE-2026-88822

Is CVE-2026-88822 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-2026-88822?

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-2026-88822?

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

QUIC Uses Uninitialized Stack Bytes During Automated Peer Detection