CVE-2026-26275Network attack vector

Message integrity bypass via unconditional digest match

Published Feb 19, 2026 · Updated Feb 19, 2026

Improper digest verification in junkurihara httpsig-hyper before 0.0.23 allows remote attackers to bypass HTTP message body integrity checks. The verify_content_digest path uses matches!(digest, _expected_digest), which binds _expected_digest as a wildcard pattern and makes every comparison succeed. The flaw is reachable only when an application relies on the library's Digest verification, allowing modified request or response bodies to pass that check even if signature validation is separate.

CVSS severity7.5
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper digest verification in junkurihara httpsig-hyper before 0.0.23 allows remote attackers to bypass HTTP message body integrity checks. The verify_content_digest path uses matches!(digest, _expected_digest), which binds _expected_digest as a wildcard pattern and makes every comparison succeed. The flaw is reachable only when an application relies on the library's Digest verification, allowing modified request or response bodies to pass that check even if signature validation is separate.

The record

CVE
CVE-2026-26275
Published
Feb 19, 2026
Updated
Feb 19, 2026
Vendor
junkurihara
Product
httpsig-hyper
Classifications
CWE-697, CWE-354, T1565.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 19, 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=< 0.0.23

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

junkurihara · httpsig-hyperversion=< 0.0.23

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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-697Incorrect Comparison
CWE-354Improper Validation of Integrity Check Value
T1565.002Transmitted Data Manipulation

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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