CVE-2026-33487goxmldsig has validateSignature Loop Variable Capture Signature Bypass
- 7.5HighCVSS base score
- 0.33%Exploitation in 30 daysEPSS · top 74% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
goxmlsig provides XML Digital Signatures implemented in Go. Prior to version 1.6.0, the `validateSignature` function in `validate.go` goes through the references in the `SignedInfo` block to find one that matches the signed element's ID. In Go versions before 1.22, or when `go.mod` uses an older version, there is a loop variable capture issue. The code takes the address of the loop variable `_ref` instead of its value. As a result, if more than one reference matches the ID or if the loop logic is incorrect, the `ref` pointer will always end up pointing to the last element in the `SignedInfo.References` slice after the loop. goxmlsig version 1.6.0 contains a patch.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
Timeline
ID reserved
By GitHub_M
- 6 days later
· 6 days later
Published
- 6 months later
· 6 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| redhat-SADPADP (enrichment) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.33% · top 74% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected < 1.6.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/russellhaering/goxmldsigGHSA-479m-364c-43vc (opens in a new tab)
References
References12
- https://github.com/russellhaering/goxmldsig/security/advisories/GHSA-479m-364c-43vc (opens in a new tab)x_refsource_CONFIRM
- https://access.redhat.com/security/cve/CVE-2026-33487 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2451814 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33487.json (opens in a new tab)x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:22423 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:22347 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:23345 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:36882 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:13548 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:20946 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:20943 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:21769 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-16281 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-479m-364c-43vc (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-33487)Record last updated .