CVE-2026-26275: 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...

Description

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 `_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.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.16%

5.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Junkurihara	Httpsig-Hyper	< 0.0.23

References

https://github.com/junkurihara/httpsig-rs/commit/5533f596c650377e02f4aa9e3eb8dba591b87370Patch
https://github.com/junkurihara/httpsig-rs/commit/65cbd19b395180a4bba09a89746c4b14ccb8d297Patch
https://github.com/junkurihara/httpsig-rs/pull/14Issue Tracking, Patch
https://github.com/junkurihara/httpsig-rs/pull/15Issue Tracking, Patch
https://github.com/junkurihara/httpsig-rs/security/advisories/GHSA-7v42-g35v-xrchVendor Advisory

Timeline

Published: Feb 19, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-26275?

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 `_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.

How severe is CVE-2026-26275?

CVE-2026-26275 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.

How do I fix CVE-2026-26275?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.