Description
When launching a Docker or OCI worker, the setuid-root worker-launcher first changes ownership of the
entire worker directory to the untrusted topology user, and only afterwards reads and acts on the command
file that the supervisor wrote into that same directory. The file is opened without O_NOFOLLOW and without
re-verifying its owner, so between the ownership change and the read the tenant can replace its contents.
For the Docker path the parsed command is executed with real uid 0, and the command sanitiser is not a
privilege boundary: it admits -v with an arbitrary source, --device, --cap-add, --security-opt,
--user and --net, and copies positional arguments through verbatim. A rewritten file therefore yields an
attacker-authored, root-equivalent container invocation with the host filesystem available.
For the OCI path the same rewrite window applies, and mount validation is structural only, with no
source or destination allow-list, so arbitrary host paths can be bind-mounted read-write into the
container. The username field of the command file is likewise attacker-settable and is checked only
against non-root and minimum-uid rules, permitting execution as another tenant's uid.
Mitigation
Upgrade to 3.1.0, where the command file is validated before the ownership change and re-verified on open,
and where mount sources and destinations are constrained by configuration.
Users who cannot upgrade immediately should disable Docker and OCI worker isolation, or restrict topology
submission on affected supervisors to trusted principals. Note that the launcher must be rebuilt and
reinstalled after upgrading.
Credit
The ASF -- found using Claude agents to study the security of open-source projects, validated and reported by Apache Storm.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
The CVE record names the fixed release. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it