Zapros, a Python HTTP client, prior to version 0.14.0 is vulnerable to denial of service when an application requests content from an untrusted server, or follows a redirect to one, because a malicious response containing an excessive number of chained Content-Encoding values causes Zapros to construct a deeply nested decompression chain that consumes excessive resources. Version 0.14.0 patches the vulnerability by limiting responses to five content-encoding layers and raising DecodingError when that limit is exceeded. As a workaround, applications can add response middleware that inspects the Content-Encoding header and rejects responses containing more than a safe number of encoding layers.
CVE-2026-61541
MEDIUMPre-NVD 6.96.9—Trending — 3 sources updated this week
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 6.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 66% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
6.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.9Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.9
- EG Score
- 6.9(medium)
- EG Risk
- 46(Track)EG Risk 46/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity69% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 34%
- KEV
- Not listed
Published
September 21, 2026
Last Modified
September 23, 2026
Advisory Details (1)
Auto-updated Sep 21, 2026Patch available. Sources: github.
github Patch Available
Unbounded Content-Encoding decompression chain allows denial of service · Advisory · kap-sh/zapros · GitHub
Affected: version 0.14.0.
https://github.com/kap-sh/zapros/security/advisories/GHSA-5vjj-2r48-q622Vendor Advisories for CVE-2026-61541(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| zapros | 0.10.0 ... 0.9.0 (17 versions) | 0.14.0 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 8× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.
- 2026-09-24 19:19 UTCEG score recompute
- 2026-09-23 20:24 UTCEG score recompute
- 2026-09-23 19:19 UTCEG score recompute
- 2026-09-23 17:54 UTCEPSS rescore
- 2026-09-22 21:22 UTCEG score recompute
- 2026-09-21 22:27 UTCEG score recompute
- 2026-09-21 21:27 UTCEG score recompute
- 2026-09-21 21:26 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same CWE)
Frequently asked(5)
What is CVE-2026-61541?
CVE-2026-61541 is a medium vulnerability published on September 21, 2026. Zapros, a Python HTTP client, prior to version 0.14.0 is vulnerable to denial of service when an application requests content from an untrusted server, or follows a redirect to one, because a malicious response containing an excessive number of chained Content-Encoding values causes Zapros to…
When was CVE-2026-61541 disclosed?
CVE-2026-61541 was first published in the National Vulnerability Database on September 21, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-61541 actively exploited?
CVE-2026-61541 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 65.7% of all scored CVEs.
What is the CVSS score of CVE-2026-61541?
CVE-2026-61541 has a CVSS v3 base score of 6.9 (NVD).
How do I remediate CVE-2026-61541?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-61541, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-61541
Is Your Infrastructure Affected by CVE-2026-61541?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.