CVE-2025-6069 | HTMLParser quadratic complexity when processing malformed inputs

The html.parser.HTMLParser class had worse-case quadratic complexity when processing certain crafted malformed inputs potentially leading to amplified denial-of-service.

Published: 2025-06-17 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-6069 is rated Low Risk (29.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.46%). 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-2025-6069

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 2026-06-15 0.86% 0.46% -0.40%
2 2026-04-13 0.25% 0.86% +0.61%
3 2026-03-03 — 0.25% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-6069

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/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:L)
A normal user session is enough; they don’t have to be admin.
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.
 2.8 1.4 [email protected]

Weakness enumeration for CVE-2025-6069

OS Trackers for CVE-2025-6069

vendor priority summary link
debian end-of-life CVE-2025-6069 end-of-life priority: Debian including 6 source packages (jython, pypy3, python2.7, python3.11, python3.13, python3.9), 16 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 8, resolved 8. https://security-tracker.debian.org/tracker/CVE-2025-6069
redhat medium — https://access.redhat.com/security/cve/CVE-2025-6069
suse medium CVE-2025-6069 severity moderate: SUSE including 641 source package names (0.0.17-1.1:libpython3_11-1_0-3.11.13-150600.3.35.1, 0.0.17-1.1:libpython3_6m1_0-3.6.15-150300.10.97.1, …), 2467 product×package rows across 399 product lines (Container bci/kiwi, Container bci/spack, … (399 product lines)): Fixed 2227, Known Affected 226, First Fixed 14. https://www.suse.com/security/cve/CVE-2025-6069/
ubuntu medium CVE-2025-6069 medium priority: Ubuntu including 13 source packages (jython, python2.7, …), 129 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 87, needs-triage 17, released 15, needed 5, ignored 4, not-affected 1. https://ubuntu.com/security/CVE-2025-6069

Affected software / configurations for CVE-2025-6069

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-6069

cvelogic Threat Intelligence