CVE-2026-41677Network attack vector

Out-of-bounds read via oversized callback length

Published Apr 24, 2026 · Updated Apr 24, 2026

Out-of-bounds read in rust-openssl openssl 0.9.0 through 0.10.77 allows remote attackers to read memory during PEM key loading. The *_from_pem_callback APIs trust the byte count returned by an application password callback and pass an oversized length to OpenSSL, which reads beyond the callback buffer. Exposure requires a consuming application to use an affected callback with a pre-3.x OpenSSL release; bounded effects include adjacent-memory disclosure and a service crash.

CVSS severity9.1
Critical
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in rust-openssl openssl 0.9.0 through 0.10.77 allows remote attackers to read memory during PEM key loading. The *_from_pem_callback APIs trust the byte count returned by an application password callback and pass an oversized length to OpenSSL, which reads beyond the callback buffer. Exposure requires a consuming application to use an affected callback with a pre-3.x OpenSSL release; bounded effects include adjacent-memory disclosure and a service crash.

The record

CVE
CVE-2026-41677
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
rust-openssl
Product
openssl
Classifications
CWE-1284, CWE-125
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.9.0, < 0.10.78

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

rust-openssl · opensslversion=>= 0.9.0, < 0.10.78

Published CVSS scores

1.7GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:U
9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1284Improper Validation of Specified Quantity in Input
CWE-125Out-of-bounds Read

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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