CVE-2026-39958
CVE-2026-39958 is a critical-severity vulnerability with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-93.
Key facts
- Severity: Critical (CVSS 3.x base score 9.1)
- CVSS v4: 5.2
- EPSS exploit prediction: 0% (28th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-20962
- Weakness: CWE-93
- Published:
- Last modified:
Description
oma is a package manager for AOSC OS. Prior to 1.25.2, oma-topics is responsible for fetching metadata for testing repositories (topics) named "Topic Manifests" ({mirror}/debs/manifest/topics.json) from remote repository servers, registering them as APT source entries. However, the name field in said metadata were not checked for transliteration. In this case, a malicious party may supply a malformed Topic Manifest, which may cause malicious APT source entries to be added to /etc/apt/sources.list.d/atm.list as oma-topics finishes fetching and registering metadata. This vulnerability is fixed in 1.25.2.
Frequently asked questions
- What is CVE-2026-39958?
- oma is a package manager for AOSC OS. Prior to 1.25.2, oma-topics is responsible for fetching metadata for testing repositories (topics) named "Topic Manifests" ({mirror}/debs/manifest/topics.json) from remote repository servers, registering them as APT source entries. However, the name field in said metadata were not checked for transliteration. In this case, a malicious party may supply a malformed Topic Manifest, which may cause malicious APT source entries to be added to /etc/apt/sources.list.d/atm.list as oma-topics finishes fetching and registering metadata. This vulnerability is fixed in 1.25.2.
- How severe is CVE-2026-39958?
- CVE-2026-39958 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
- Is CVE-2026-39958 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-39958?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- Does CVE-2026-39958 have an EU (EUVD) identifier?
- Yes. CVE-2026-39958 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20962.
- When was CVE-2026-39958 published?
- CVE-2026-39958 was published on 2026-04-09 and last updated on 2026-06-17.
References
- https://github.com/AOSC-Dev/oma/commit/b361c0f219bbf91a684610c76210f71f093dbc18
- https://github.com/AOSC-Dev/oma/pull/733
- https://github.com/AOSC-Dev/oma/releases/tag/v1.25.2
- https://github.com/AOSC-Dev/oma/security/advisories/GHSA-86jc-7r6q-cr3f
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