Security Digest · Vulnerability record
CVE-2026-58426: Gitea Actions Artifacts V4 signed URL HMAC ambiguity allows cross-repository artifact read and cross-task upload-state write
Gitea Actions Artifacts V4 signed URL HMAC ambiguity allows cross-repository artifact read and cross-task upload-state write
CVSS 9.6 Critical EPSS 0.3% · p22
Should you act?
Critical, preconditions apply
Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.3%, percentile 22: FIRST’s model estimates a 0.3% chance of exploitation activity in the next 30 days, higher than 22% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes
code.gitea.io/gitea(Go) >= 1.22.0, < 1.26.2, fixed in 1.26.2. Check your lockfile, including transitive dependencies.
What it is
Gitea Actions Artifacts V4 signed URL HMAC ambiguity allows cross-repository artifact read and cross-task upload-state write
From the GitHub advisory
Summary
Gitea Actions Artifacts V4 signed upload/download URLs can be rewritten to access a different running task and repository context while preserving the original HMAC signature. An attacker with permission to run a Gitea Actions job can turn a signed URL for an attacker-controlled artifact into a URL that reads artifacts from another task context, or writes attacker-controlled data into another task's artifact upload staging context, including in a private repository.
This is one vulnerability with two exploit paths:
- DownloadArtifact: cross-task/cross-repository artifact read, giving C:H. - UploadArtifact: cross-task artifact staging write and metadata mutation, giving I:H.
Details
Weakness type: CWE-347.
Product: code.gitea.io/gitea (Go) · Assigned by: Gitea · Published: 2026-07-03
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Go | code.gitea.io/gitea | >= 1.22.0, < 1.26.2 | 1.26.2 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| Gitea | Gitea Open Source Git Server | 1.22.0 <= 1.26.1 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| Gitea | 3.1 | 9.6 Critical | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N |
| GitHub | 3.1 | 9.6 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: low (any account)
- User interaction: none
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.30% probability of exploitation activity in the next 30 days; percentile 22.
Timeline
- — CVE record published by Gitea
- — CVE record last updated
- — GitHub-reviewed advisory GHSA-hg5r-vq93-9fv6 published (critical)
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- GitHub Security Advisory github.com
- GitHub Pull Request #37707 github.com
- Gitea v1.26.2 Release github.com
- Gitea v1.26.2 Release Blog Post blog.gitea.com
Vulnerability records
- GitHub Advisory GHSA-hg5r-vq93-9fv6 github.com
- CVE.org record CVE-2026-58426 cve.org
- NVD entry CVE-2026-58426 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com