A privilege escalation vulnerability existed in the Below service prior to v0.9.0 due to the creation of a world-writable directory at /var/log/below. This could have allowed local unprivileged users to escalate to root privileges through symlink attacks that manipulate files such as /etc/shadow.
CVE-2025-27591
“▲” beside the score: it is higher than NVD's CVSS score.
Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2025-03-11. NVD baseline CVSS 6.8; sources differ by 1.0.
Also known asEUVD-2025-7209 (ENISA EUVD) · GHSA-9mc5-7qhg-fp3w (GitHub Security Advisories)Source: ENISA EUVD
- Public exploit or proof-of-concept code is available
A fix is available — apply it.
- CVSS v3
- 6.8
- EG Score
- 7.8HIGHmedium confidence
- EG Risk
- 51EG Risk 51/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity78% × 45%Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).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.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.4%
- EPSS %ILE
- 31st
- KEV
- Not listed
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
- 0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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).
A fix is available. 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
Published
March 11, 2025
Last Modified
July 3, 2025
Advisory Details (3)
Auto-updated Oct 24, 2026oss-security - Below: World Writable Directory in /var/log/below Allows Local Privilege Escalation (CVE-2025-27591)
http://www.openwall.com/lists/oss-security/2025/03/12/1commit da9382e6e3e3 (facebookincubator/below)
Patch available: facebookincubator/below v0.9.0 (contains commit da9382e6e3e3)
https://github.com/facebookincubator/below/commit/da9382e6e3e332fd2c3195e22f34977f83f0f1f3Patch Availability(1)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| rust | below @ 0.9.0 (fixes < 0.9.0) | — | ghsa |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
crates.io(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| below | — |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 38× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 96 of 192 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 4 repeat rows among the latest 100 are merged into the row they repeat. The 96 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-11-01 08:08 UTCGHSA enrichmentGHSA-9mc5-7qhg-fp3w · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-11-01 08:08 UTCEG score recompute▲ 1.00
- 2026-10-31 16:31 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-30 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-29 16:31 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-28 16:30 UTCEPSS rescoreEPSS 0.4% · 31st percentile
- 2026-10-27 16:30 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-26 16:29 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-25 16:38 UTCEG score recompute
- 2026-10-25 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-24 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-24 00:34 UTCEG score recompute
- 2026-10-23 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-22 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-21 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-20 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-19 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-18 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-18 05:41 UTCEG score recompute
- 2026-10-17 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-16 16:38 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-15 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-13 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
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- 2026-10-12 17:14 UTCEG score recompute
- 2026-10-12 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-11 20:46 UTCEG score recompute
- 2026-10-11 18:56 UTCEG score recompute
- 2026-10-11 15:34 UTCEG score recompute
- 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-08 17:09 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-07 23:46 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-06 15:16 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-10-03 14:24 UTCEPSS rescoreEPSS 0.4% · 27th percentile
- 2026-10-02 20:25 UTCOSV refresh
- 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.4% · 27th percentile
- 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.4% · 27th percentile
- 2026-09-29 15:19 UTCEPSS rescoreEPSS 0.4% · 27th percentile
- 2026-09-28 13:50 UTCEPSS rescoreEPSS 0.4% · 27th percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 27th percentile
- 2026-09-26 00:24 UTCEPSS rescoreEPSS 0.4% · 27th percentile
- 2026-09-24 14:02 UTCEPSS rescoreEPSS 0.4% · 27th percentile
- 2026-09-23 13:47 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-09-16 05:13 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-13 17:54 UTCOSV refresh
- 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-11 09:35 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-10 09:33 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-08 21:59 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-07 16:00 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-06 13:46 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-04 05:05 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-30 19:16 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-30 01:21 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-28 21:40 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-27 14:24 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-26 14:45 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-25 19:10 UTCOSV refresh
- 2026-08-25 13:48 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-24 14:16 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-23 00:18 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-21 23:48 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-18 13:47 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-17 13:46 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-16 14:55 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-16 02:13 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-15 01:29 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-13 21:59 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-08-10 23:59 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-08-09 13:45 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-08-09 11:37 UTCOSV refresh
- 2026-08-07 16:26 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-08-05 19:16 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-08-04 15:09 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-08-04 10:37 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-08-03 10:35 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-08-02 02:26 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-08-01 04:15 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-07-30 16:27 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-07-30 01:29 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-07-28 15:35 UTCEPSS rescoreEPSS 0.4% · 28th percentile
Publicly available exploits
(11 references, 10 shown)Public exploit code is referenced for this CVE (11 GitHub PoCs). Defenders should treat patch urgency accordingly.
- GitHub PoC0x00Jeff/CVE-2025-27591Published Nov 19, 2025
self cleaning CVE-2025-27591 Poc that grants a root reverse shell instead of modifying passwd files
Open source ↗ - GitHub PoC0xDTC/Below-Logger-Symlink-Attack_CVE-2025-27591Published Nov 13, 2025
A Bash-based privilege escalation exploit targeting the `below` system performance monitoring tool. This refurbished exploit leverages a symlink vulnerability in the logging mechanism to inject a root user into `/etc/passwd`, achieving full root access.
Open source ↗ - GitHub PoCVisaiCyber/CVE-2025-27591-below-Published Sep 3, 2025
Local Privilege Escalation vai `below` (CVE-2025-27591) - PoC Exploit
Open source ↗ - GitHub PoCCythonic1/CVE-2025-27591Published Jul 31, 2025
a C exploit for CVE-2025-27591, which allow an attacker to escalate privilege to root.
Open source ↗ - GitHub PoC00xCanelo/CVE-2025-27591Published Jul 19, 2025
🔥 Local Privilege Escalation Exploit for CVE-2025-27591 | Abuses world-writable log dir in Below to gain root via /etc/passwd injection
Open source ↗ - GitHub PoCincommatose/CVE-2025-27591-PoCPublished Jul 18, 2025
A Proof of Concept for CVE-2025-27591, a local privilege escalation in Below < v0.9.0
Open source ↗ - GitHub PoCdollarboysushil/Linux-Privilege-Escalation-CVE-2025-27591Published Jul 15, 2025
CVE-2025-27591 is a known privilege escalation vulnerability in the Below service (version < v0.9.0)
Open source ↗ - GitHub PoCBridgerAlderson/CVE-2025-27591-PoCPublished Jul 13, 2025
CVE-2025-27591 is a privilege escalation vulnerability that affected the Below service before version 0.9.0
Open source ↗ - GitHub PoCobamalaolu/CVE-2025-27591Published Jul 12, 2025
CVE-2025-27591
Open source ↗ - GitHub PoCrvizx/CVE-2025-27591Published Jul 12, 2025
Below v0.8.1 - Local Privilege Escalation (CVE-2025-27591) - PoC Exploit
Open source ↗
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2025-27591?
When was the CVE record for CVE-2025-27591 published?
Is CVE-2025-27591 actively exploited?
What is the CVSS score of CVE-2025-27591?
How do I remediate CVE-2025-27591?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-27591
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