CVE-2026-26275
Junkurihara Httpsig-Hyper ≤ 0.0.23
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NSummary
CVE-2026-26275 is a high-severity Improper Validation of Integrity Check Value (CWE-354) vulnerability in Junkurihara Httpsig-Hyper. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Supply Chain Compromise (T1195); ranked at the 6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SC-13 (Cryptographic Protection) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-26275 affects httpsig-hyper, a Hyper extension for HTTP message signatures, in versions prior to 0.0.23. The vulnerability stems from a misuse of Rust's `matches!` macro in Digest header verification, where the comparison `if matches!(digest, _expected_digest)` incorrectly treats `_expected_digest` as a pattern binding rather than performing a value comparison. This results in unconditional success of the match expression, causing digest verification to return success even when the computed digest does not match the expected value. Consequently, applications relying on this library for Digest verification as part of HTTP message signature validation may fail to detect modifications to the message body.
Remote attackers require no privileges or user interaction to exploit this issue over the network with low complexity, as indicated by its CVSS 3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N). Exploitation allows an attacker to send HTTP messages with tampered bodies that pass Digest verification, bypassing integrity checks tied to HTTP message signatures. This can lead to successful message body modification without detection, with impact limited to high integrity violation and associated CWEs-354 (Improper Validation of Integrity Check Value) and CWE-697 (Incorrect Comparison).
The security advisory and patch details in the httpsig-rs GitHub repository confirm the fix in version 0.0.23, which replaces the erroneous `matches!` usage with a proper value comparison and adds constant-time comparison for defense-in-depth, along with regression tests. Users are strongly advised to upgrade immediately, as there is no reliable workaround; those unable to upgrade should avoid relying solely on Digest verification and enforce full HTTP message signature validation at the application layer. Relevant references include the fixing commits, pull requests, and the GHSA-7v42-g35v-xrch advisory.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8435
Vulnerability Data
httpsig-hyper is a hyper extension for http message signatures. An issue was discovered in `httpsig-hyper` prior to version 0.0.23 where Digest header verification could incorrectly succeed due to misuse of Rust's `matches!` macro. Specifically, the comparison `if matches!(digest, _expected_digest)` treated…
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`_expected_digest` as a pattern binding rather than a value comparison, resulting in unconditional success of the match expression. As a consequence, digest verification could incorrectly return success even when the computed digest did not match the expected value. Applications relying on Digest verification as part of HTTP message signature validation may therefore fail to detect message body modification. The severity depends on how the library is integrated and whether additional signature validation layers are enforced. This issue has been fixed in `httpsig-hyper` 0.0.23. The fix replaces the incorrect `matches!` usage with proper value comparison and additionally introduces constant-time comparison for digest verification as defense-in-depth. Regression tests have also been added to prevent reintroduction of this issue. Users are strongly advised to upgrade to the patched version. There is no reliable workaround without upgrading. Users who cannot immediately upgrade should avoid relying solely on Digest verification for message integrity and ensure that full HTTP message signature verification is enforced at the application layer.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 10 hardening rules · 4 OS baselines
V10.4.12
Mitigating Controls (NIST 800-53 r5) AI
Requires integrity verification tools that detect unauthorized changes when checksum validation is missing or flawed.
Developer testing and evaluation directly exercises security-relevant comparisons to discover incorrect logic.
Mandates cryptographic mechanisms that include integrity protection, preventing improper checksum validation.
Requires protection of transmitted information integrity, directly mandating correct validation of integrity checks.
A reference monitor must be small and correct, structurally limiting the chance of flawed comparison logic in authorization decisions.
Security engineering principles require correct implementation of comparison logic used for access and authentication decisions.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Requires cryptographic hashes and signatures that directly enforce integrity-check validation for data at rest.
Requires cryptographic hashes and signatures that directly enforce integrity-check validation for data in transit.
Secure development practices directly require correct logic for security comparisons and thereby prevent this class of flaw.
Mandates pre-acquisition integrity assessment, addressing only the initial portion of the weakness lifecycle.
Requires verification of backup integrity, covering validation only within recovery scenarios.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Cryptographic controls mandate integrity mechanisms whose correct validation directly prevents CWE-354.
Secure coding standards require proper implementation and validation of checksums or MACs.
Security testing can detect missing integrity validation but does not itself implement the control.
Secure development lifecycle includes code review and testing that can catch incorrect comparison logic.
Application security requirements include integrity checks on messages and data, mitigating improper validation.
Secure architecture principles can require robust comparison mechanisms for access decisions.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-354
- V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354
Oracle Linux 9 (1 rule)
- V-271523 OL 9 must check the GPG signature of locally installed software packages before installation. prevents CWE-354
RHEL 7 (2 rules)
- V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354
- V-204448 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354
RHEL 8 (2 rules)
- V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354
- V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-354