CVE-2025-26803

The http parser in Phusion Passenger 6.0.21 through 6.0.25 before 6.0.26 allows a denial of service during parsing of a request with an invalid HTTP method.

Published: 2025-02-24 Last update: 2025-02-28 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-26803 is rated Low Risk (39/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.27%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-26803

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-06 0.19% 0.27% +0.08%
2 2026-04-04 0.50% 0.19% -0.31%
3 2026-03-30 — 0.50% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-26803

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-26803

GitHub Security Advisory for CVE-2025-26803

GHSA-2cj2-qqxj-5m3r · Severity: medium · Ecosystem: rubygems — Phusion Passenger denial of service

OS Trackers for CVE-2025-26803

vendor priority summary link
debian unimportant CVE-2025-26803 unimportant priority: Debian including 1 source packages (passenger), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-26803
suse medium — https://www.suse.com/security/cve/CVE-2025-26803/
ubuntu medium CVE-2025-26803 medium priority: Ubuntu including 1 source packages (passenger), 9 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, questing, upstream, xenial): not-affected 6, ignored 1, needed 1, released 1. https://ubuntu.com/security/CVE-2025-26803

Affected software / configurations for CVE-2025-26803

Vendor Product Version Raw CPE
phusion passenger >= 6.0.21, < 6.0.26 cpe:2.3:a:phusion:passenger:*:*:*:*:*:*:*:*

References for CVE-2025-26803

cvelogic Threat Intelligence