# CVE-2026-78367: Rpm: rpmbuild gettarspec() crafted tar member name → macro injection

Status: published. Published: 2026-08-24. Updated: 2026-11-06.

A vulnerability was found in RPM's rpmbuild tarball processing. When processing a crafted source archive, the getTarSpec() function in tools/rpmbuild.cc passes an attacker-controlled tar archive member name to rpmExpand() as part of a %{basename:...} macro expression. A specially crafted .spec member name can therefore inject RPM macros, including Lua expressions, resulting in arbitrary code execution with the privileges of the user running rpmbuild. This can be exploited when a victim or automated build system processes an attacker-controlled source tarball using rpmbuild tarball mode (such as -ts, -ta, or -tb).

## Remediation

- workaround: Do not process untrusted tarballs with rpmbuild -ta/-tb/-ts. Extract and inspect archives first (reject member names containing }, %, or {), or build from a reviewed .spec outside tarball mode. Prefer isolated builders (mock/container) for any untrusted packaging related work. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Hardened Images (rpm-main): ≥ 6.1.0-1.3.hum1; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 10 (rpm): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (rpm): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (rpm): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (rpm): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (rpm): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 7 (high); CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.20% as of 2026-11-05; percentile 9.76%

- SSVC: exploitation poc; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-94

## Exploit evidence

- exploit: https://github.com/rpm-software-management/rpm/issues/4314 (ADP: CISA-ADP)

## References

- https://access.redhat.com/errata/RHSA-2026:82378 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-78367 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2521857 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://github.com/rpm-software-management/rpm/issues/4314 (CNA: redhat)

- https://github.com/rpm-software-management/rpm/issues/4314 (ADP: CISA-ADP; exploit)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-78367; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-78367; retrieved 2026-11-06; source updated Not reported

Revision: e0fa0e0d3920c691b36e6537cb0fc0b12014bd64708c0361212fa726fa3d991a

Canonical: https://y2.dev/cve/CVE-2026-78367

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