perl: regexp matching hangs indefinitely on illegal UTF-8 input
Published May 25, 2016
7.5
HIGHCVSS 3.0
EPSS 2.55%
Description
The (1) S_reghop3, (2) S_reghop4, and (3) S_reghopmaybe3 functions in regexec.c in Perl before 5.24.0 allow context-dependent attackers to cause a denial of service (infinite loop) via crafted utf-8 data, as demonstrated by "a\x80."
Affected products
No data.
Configuration 1
- 22
No data.
Red Hat Hardened Images
perl-main-1.03-524.hum1
Fixed · RHSA-2026:6206
Red Hat Directory Server 8
perl
Will not fix
Red Hat Enterprise Linux 5
perl
Will not fix
Red Hat Enterprise Linux 6
perl
Will not fix
Red Hat Enterprise Linux 7
perl
Will not fix
Red Hat Software Collections
perl516-perl
Will not fix
Red Hat Software Collections
rh-perl520-perl
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Hardened Images | perl-main-1.03-524.hum1 | Fixed | RHSA-2026:6206 |
| Red Hat Directory Server 8 | perl | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | perl | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | perl | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | perl | Will not fix | n/a |
| Red Hat Software Collections | perl516-perl | Will not fix | n/a |
| Red Hat Software Collections | rh-perl520-perl | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:L/Au:N/C:N/I:N/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (23 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 2.55% (0.02553) | 84.49th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.57% (0.02574) | 83.10th | v5 (v2026.06.15) |
| Dec 28, 2025 | 13.99% (0.13990) | 94.11th | v4 (v2025.03.14) |
| Dec 27, 2025 | 5.14% (0.05140) | 89.57th | v4 (v2025.03.14) |
| Dec 10, 2025 | 13.99% (0.13990) | 94.08th | v4 (v2025.03.14) |
| Oct 28, 2025 | 9.10% (0.09098) | 92.29th | v4 (v2025.03.14) |
| Oct 27, 2025 | 5.14% (0.05140) | 89.42th | v4 (v2025.03.14) |
| Oct 1, 2025 | 9.10% (0.09098) | 92.39th | v4 (v2025.03.14) |
| Jul 30, 2025 | 5.14% (0.05140) | 89.46th | v4 (v2025.03.14) |
| Jul 12, 2025 | 7.59% (0.07592) | 91.40th | v4 (v2025.03.14) |
| Mar 30, 2025 | 10.53% (0.10529) | 92.56th | v4 (v2025.03.14) |
| Mar 29, 2025 | 22.84% (0.22841) | 93.36th | v4 (v2025.03.14) |
| Mar 17, 2025 | 10.53% (0.10529) | 92.70th | v4 (v2025.03.14) |
| Dec 12, 2024 | 3.48% (0.03483) | 91.88th | v3 (v2023.03.01) |
| Jun 24, 2024 | 3.48% (0.03483) | 91.58th | v3 (v2023.03.01) |
| Nov 5, 2023 | 3.05% (0.03050) | 89.89th | v3 (v2023.03.01) |
| Jul 18, 2023 | 2.17% (0.02174) | 87.84th | v3 (v2023.03.01) |
| Apr 28, 2023 | 1.93% (0.01931) | 86.89th | v3 (v2023.03.01) |
| Mar 16, 2023 | 1.81% (0.01815) | 86.30th | v3 (v2023.03.01) |
| Mar 7, 2023 | 1.76% (0.01761) | 86.02th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.69% (0.02686) | 82.85th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.69% (0.02686) | 81.17th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.69% (0.02686) | 62.66th | v2 (v2022.01.01) |
References (16)
- http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183592.html vendor-advisoryx_refsource_FEDORA
- http://perl5.git.perl.org/perl.git/commitdiff/22b433eff9a1ffa2454e18405a56650f07b385b5 x_refsource_CONFIRMVendor Advisory
- http://www.openwall.com/lists/oss-security/2016/04/20/5 mailing-listx_refsource_MLIST
- http://www.openwall.com/lists/oss-security/2016/04/20/7 mailing-listx_refsource_MLIST
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html x_refsource_CONFIRM
- http://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html x_refsource_CONFIRM
- http://www.securityfocus.com/bid/86707 vdb-entryx_refsource_BID
- https://access.redhat.com/security/cve/CVE-2015-8853 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1329106 x_refsource_CONFIRMIssue Tracking
- https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731 x_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2015-8853
- https://rt.perl.org/Public/Bug/Display.html?id=123562 x_refsource_CONFIRM
- https://security.gentoo.org/glsa/201701-75 vendor-advisoryx_refsource_GENTOO
- https://usn.ubuntu.com/3625-1/ vendor-advisoryx_refsource_UBUNTU
- https://usn.ubuntu.com/3625-2/ vendor-advisoryx_refsource_UBUNTU
- https://www.cve.org/CVERecord?id=CVE-2015-8853
Change history (0)
No recorded changes yet.