WebOb provides objects for HTTP requests and responses. Prior to 1.8.11, Response._make_location_absolute() in src/webob/response.py checks a Location value for a URI scheme or leading double slash before urllib.parse.urljoin() strips leading C0 control characters and spaces. An attacker-controlled value such as a space followed by a protocol-relative or absolute URL can therefore bypass SCHEME_RE and startswith("//") checks and be normalized to an off-host redirect. Request.relative_url() and webob.exc._HTTPMove subclasses, including HTTPFound, are also affected because they use the same unsafe URL joining behavior or bypass the earlier normalization path. An unauthenticated attacker who can influence an application's redirect target can send users to an attacker-controlled host for phishing or OAuth and SSO token theft, but exploitation requires the user to follow the redirect. This issue is fixed in version 1.8.11.
CVE-2026-54770
“—” beside the score: it is equal to the CVSS score beside it.
Score 6.1 from GitHub Security Advisory (severity: MODERATE) published 2026-08-27. A secondary CVSS source baseline 6.1; sources differ by 0.0.
Also known asEUVD-2026-63467 (ENISA EUVD) · GHSA-6hx8-3wjj-gr8g (GitHub Security Advisories) · PYSEC-2026-3943 (OSV.dev)Source: ENISA EUVD
- CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
A fix is available — apply it.
- CVSS v3
- 6.1
- EG Score
- 6.1MEDIUMmedium confidence
- EG Risk
- 43EG Risk 43/100
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)Severity61% × 45%Impact severity (EG Severity): CVSS 6.1 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 public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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
- 36th
- 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 (6.1): severity, escalated by confirmed exploitation. This CVE's 6.1 is its impact severity (EG Severity), not escalated.
- EG Severity
- 6.1 MEDIUMCVSS-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: 60 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 public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (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)60 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 partial (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
August 20, 2026
Last Modified
October 18, 2026
Advisory Details (3)
Auto-updated Aug 20, 2026commit ff89560643fb (Pylons/webob)
Fix landed in Pylons/webob commit ff89560643fb — awaiting tagged release
https://github.com/Pylons/webob/commit/ff89560643fb252751b4db8806a283b5377f1f07Open redirect in Location header normalization via leading C0 control / space characters -- third times a charm? · Advisory · Pylons/webob · GitHub
https://github.com/Pylons/webob/security/advisories/GHSA-6hx8-3wjj-gr8gVendor Advisories for CVE-2026-54770(8)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:81110Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.18.1
- RHSA-2026:79546Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.12.23
- RHSA-2026:79366Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.10.27
- RHSA-2026:77656Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.9.27
- RHSA-2026:74511Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.17.5
- RHSA-2026:69255Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Quay 3.16.6
- GHSA-6hx8-3wjj-gr8gGitHub Security AdvisoriesMedium
WebOb: Open redirect in Location header normalization via leading C0 control / space characters
- CVE-2026-54770Microsoft Security Response Center (MSRC)Medium
WebOb: Open redirect in Location header normalization via leading C0 control / space characters
Patch Availability(7)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | quay/quay-rhel9:1791265590 | 2026-10-12 | redhat |
| redhat | quay/quay-rhel8:1791462428 | 2026-10-08 | redhat |
| redhat | quay/quay-rhel8:1791314514 | 2026-10-08 | redhat |
| redhat | quay/quay-rhel8:1790808443 | 2026-10-07 | redhat |
| redhat | quay/quay-rhel9:1790690298 | 2026-10-01 | redhat |
| redhat | quay/quay-rhel9:1789563753 | 2026-09-21 | redhat |
| pip | webob @ 1.8.11 (fixes < 1.8.11) | — | 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
(4 across 4 ecosystems)
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-webob | 1:1.8.10-1 ... 1:1.8.9-2 (8 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-webob | 1:1.8.10-0+deb13u1, 1:1.8.10-1, 1:1.8.11-1, 1:1.8.9-1, 1:1.8.9-2 |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-webob | 1:1.8.10-1, 1:1.8.9-1, 1:1.8.9-2 |
| — |
PyPI(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| webob | 0.8 ... 1.8.9 (74 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 50× 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 99 of 134 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 35 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-11-01 07:44 UTCGHSA enrichmentGHSA-6hx8-3wjj-gr8g · GitHub severity MODERATE · GitHub CVSS 6.1
- 2026-11-01 07:44 UTCEG score recompute
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-28 04:25 UTCOSV refresh
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
- 2026-10-25 14:19 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
- 2026-10-18 20:36 UTCEG score recompute
- 2026-10-18 20:36 UTCVendor advisory
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-18 03:30 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
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- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-12 15:56 UTCEG score recompute
- 2026-10-11 19:39 UTCEG score recompute
- 2026-10-11 16:54 UTCEG score recompute
- 2026-10-11 14:17 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-08 06:06 UTCEG score recompute
- 2026-10-08 06:06 UTCVendor advisory
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-07 04:47 UTCEG score recompute
- 2026-10-07 04:47 UTCVendor advisory
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-06 03:27 UTCEG score recompute
- 2026-10-06 03:27 UTCVendor advisory
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-04 20:52 UTCVendor advisory
- 2026-10-03 16:47 UTCEG score recompute
- 2026-10-03 16:47 UTCVendor advisory
- 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-02 11:05 UTCEG score recompute
- 2026-10-02 11:05 UTCVendor advisory
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-10-01 09:30 UTCEG score recompute
- 2026-10-01 09:30 UTCVendor advisory
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 34th percentile
- 2026-09-30 08:14 UTCEG score recompute
- 2026-09-30 08:14 UTCVendor advisory
- 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-29 05:37 UTCEG score recompute
- 2026-09-29 05:37 UTCVendor advisory
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-28 04:20 UTCEG score recompute
- 2026-09-28 04:20 UTCVendor advisory
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
- 2026-09-27 03:03 UTCEG score recompute
- 2026-09-27 03:03 UTCVendor advisory
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-25 04:02 UTCEG score recompute
- 2026-09-25 04:02 UTCVendor advisory
- 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 28th percentile
- 2026-09-24 02:45 UTCEG score recompute
- 2026-09-24 02:45 UTCVendor advisory
- 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-23 01:29 UTCEG score recompute
- 2026-09-23 01:29 UTCVendor advisory
- 2026-09-22 00:12 UTCEG score recompute
- 2026-09-22 00:12 UTCVendor advisory
- 2026-09-20 22:53 UTCEG score recompute
- 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-19 21:36 UTCEG score recompute
- 2026-09-18 20:20 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-18 13:30 UTCEG score recompute
- 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-17 12:13 UTCEG score recompute
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-16 10:53 UTCEG score recompute
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-15 09:36 UTCEG score recompute
- 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-14 08:19 UTCEG score recompute
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 27th percentile
- 2026-09-13 07:03 UTCEG score recompute
- 2026-09-12 05:47 UTCEG score recompute
- 2026-09-11 04:30 UTCEG score recompute
- 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.3% · 26th percentile
- 2026-09-09 01:57 UTCEG score recompute
Related CVEs(same product + same vendor + same CWE)
Same vendor
10 shownredhat:RHSA-2026:74511 · redhat:RHSA-2026:69255 · redhat:RHSA-2026:77656
Frequently asked(5)
What is CVE-2026-54770?
When was the CVE record for CVE-2026-54770 published?
Is CVE-2026-54770 actively exploited?
What is the CVSS score of CVE-2026-54770?
How do I remediate CVE-2026-54770?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-54770
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